COMBAT MilTerms: Parachuting, Skydiving, and Soaring Terms

A Glossary of Parachuting, Skydiving, and Soaring Terms

ParaTerms

AAD :: Automatic Activation Device; also known as Automatic Opening Device (AOD). A self-contained "fail-safe" device (eg: CYPRES, ASTRA, Sentinel, Irvin Height-Finder, FF-1, F1B, etc) that's positioned within the auxiliary container so as to sense the skydiver's altitude and rate of descent, and is designed to mechanically (or electromechanically) activate the reserve parachute at graduated preset intervals of elapsed time, excess velocity, or minimum altitude, if the skydiver does not deactivate or disengage it during normal descent.
A/C :: The abbreviation for aircraft; any machine or device, including airplanes, helicopters, gliders, balloons or dirigible, that's capable of atmospheric flight. Also referred to as "jump plane" or "jump ship" when performing that role. Parachutes and other airfoils are not classified as aircraft.
Accelerated Free Fall :: See AFF.
accuracy :: Accuracy landings of varying difficulty, from 20 meters to 2 meters, are required for USPA license advancements; also known as "precision landing" or "precision jumping". A competitive event in which a skydiver attempts to land on (or as close to) an established (3cm diameter) target from a designated release point; in national competition, gradations are measured in centimeters.
ACP :: The abbreviation for Air Control Point, being the racetrack flight pattern employed during assembly, discharge, monitoring, and observation.
ADEPT :: The abbreviation for Alternate Door Exit Procedure for Training.
aerobatics :: The skill maneuvers essential for controlled aerial movement during a skydiver's descent; the mastery of which is required for Relative Work (RW), and a prerequisite for USPA license advancements. A competitive event in which a skydiver performs a prearranged sequence of maneuvers within a stipulated time period; also known as freestyle or "style" competition. A feat or stunt displaying a person's skill, dexterity, or daring during aerial descent.
aerodynamics :: The study of the motion of air (and other gases) and of its effects on bodies (and other objects) in that medium. [v: celestial mechanics]
aerostat :: Any lighter-than-air aircraft, such as a balloon or dirigible.
aerotow / aero-tow :: The towing of a glider (sailplane or hang glider) by a powered aircraft or wind-driven balloon to a height suitable for disconnect launching from the towline; as distinguished from catapult, winch, or ground vehicle assisted launching. Glider tow positions are either below ("low-tow") or above ("high-tow") the wake of the tow plane.
AFF :: Accelerated Free Fall, also called "harness hold", developed as a training modality by Ken Coleman; being one of the Instructor Assisted Deployment (IAD) techniques. An AFF student is trained in freefall techniques and landings by accompanied jumps with a qualified jumpmaster on actual descents lasting 20 to 40 seconds or longer, as opposed to static line training; also known as "Accelerated Skydiving Program" (ASP).
AFF CC :: The USPA certification course that must be successfully completed in order for a jumpmaster to be qualified to conduct Accelerated Free Fall (or Instructor Assisted Deployment) skydiving techniques with a student.
AGL :: Above Ground Level. Altitudes are calculated in reference to either "ground level" or "sea level"; but skydivers always use AGL when referring to jump altitude.
AGU :: The Airborne Guidance Unit, or Autonomous Guidance Unit, is an integral part of the Joint Precision AirDrop System (JPADS), housing a Global Positioning System (GPS) receiver, the guidance – navigation and control (GN&C) software package, the actuator hardware required to operate the steering lines, and the battery power pack, which directs the para-dropped payload along its plotted trajectory onto its designated drop zone (DZ) ... minor corrections may be input by ground controllers using a laser aiming device.
airborne :: A military force carried to the battlefield in gliders or by parachute from aircraft; abbreviated "ABN".
airborne shuffle :: A gliding walk, without lifting the feet, toward the exit of an aircraft in flight, when the JUMPMASTER directs the paratroopers to jump above the drop zone (DZ); this sliding gait is used to improve security and sustain balance on an unstable cargo DECK, and to avoid tripping or stumbling during the crucial interval between hookup and departure. Also, slang for the moderately paced jog that's performed as a routine part of daily exercise. Also, informal expression, by extension of the jogging formation, for the tempo when an individual hurries his walking pace or slows from a running pace; to scuff, shamble, or scramble.
airchair / air-chair :: See ultralight.
aircraft :: any machine supported for flight in the air by buoyancy or by the dynamic action of air on its surfaces; an A/C.
air current :: A mass of air flowing in a certain direction and moving at a certain speed (velocity of flow), which may be caused by differences in temperature, pressure, or a concentration of impurities.
airdrop :: The delivery of personnel and/or equipment by parachute onto a drop zone (DZ) from an aircraft in flight, as in airborne transport or reinforcement, or in aerial supply or resupply; also called para-drop.
airfoil :: Any surface, as a wing or stabilizer, designed to aid in lifting or thrusting, controlling or stabilizing an airborne body or craft, by making use of the air currents through which it moves.
airframe :: The rigid primary structure that forms the shape of an aircraft, supporting its rigid or flexible wing(s), which enclosing framework may be covered by a fairing, nacelle, or the like.
airhead :: The secure initial position of an airborne assault into contested territory, used for further advancement and resupply; a tactical foothold established by vertical assault.
air mass :: a body of air covering a wide area that exhibits relatively uniform properties throughout any section thereof.
airplane :: A heavier-than-air vehicle that's variously propelled into aerodynamic flight; an A/C.
air pocket :: A nearly vertical current of air that can cause a flying object to suddenly lose altitude.
airspace :: The region of the atmosphere above an area of land and/or water, especially the atmospheric region above a nation over which it has jurisdiction.
airspeed :: The forward speed of an object relative to the air through which it is flying; commonly used in reference to canopies, airfoils, or aircraft.
airstream :: Any localized airflow; also spelled "air-stream" and "air stream".
airworthy :: Equipment that was produced and has been maintained in a condition to tolerate the aerodynamic stresses of flight.
A license :: The initial rating by the U.S. Parachute Association (USPA) signifying that a skydiver has advanced beyond the student phase of training, and is able to pack their own main parachute, to jumpmaster themselves, to perform basic group freefall jumps, to make water landings, and to participate in certain collegiate competitions; the license of physically impaired skydivers may be restricted (A####R) to ensure safety.
alteration :: Any change or modification to any part of the parachute assembly from its original manufacturer's specifications that might appreciably affect weight, structural strength, performance, flight characteristics, or other qualities affecting airworthiness; any major or minor alteration that's not the result of repair.
altimeter :: An aneroid or radio barometer used to ascertain altitude, especially height above the drop zone.
altitude :: The height of something above the earth's surface; altitudes are calculated 'above ground level' (AGL) by parachutists and at 'mean sea level' (MSL) by aircraft pilots.
altitude alarm :: A device programmed to warn the jumper when reaching critical altitude for deployment of the backup chute; this audible or audiovisual signal may be mounted on the skydiver's wrist, helmet, or reserve.
AN :: The abbreviation for Aircraft Nomenclature; being the designation stamped on hardware to specify that it's of aircraft quality, and capable of tolerating aerodynamic stresses.
anabatic :: A wind or air current that is moving upward; compare "katabatic".
angel :: Slang for altitude expressed in thousands of feet above ground level (AGL).
angle of attack :: The acute angle between the chord of an airfoil or wing and the direction of airflow; the angle at which the wing or airfoil is presented to the apparent wind; the amount of pitch at which an airfoil is flying, which efficiency can be optimized. With square parachutes this angle changes when the brakes are applied.
angle of incidence :: The angle at which a canopy or airfoil is trimmed to glide through the air; the relative pitch (leading edge up or down) angle of an airfoil or wing measured between the chord line and the horizon.
anti-inversion net :: a component of the Parachute Troop Harness for the T-10 parachute, together with Capewell Canopy Releases (which allowed the main canopy to be jettisoned), which prevented the paratrooper from rotating over the canopy upon descent from the airplane; designed and developed by CW4 John Ashley Ward, who also developed steerable parachute systems for later models.
AOD :: Automatic Opening Device; also known as Automatic Activation Device (AAD). A self-contained "fail-safe" device (eg: CYPRES, ASTRA, Sentinel, Irvin Height-Finder, FF-1, F1B, etc) that's positioned within the auxiliary container so as to sense the skydiver's altitude and rate of descent, and is designed to mechanically (or electromechanically) activate the reserve parachute at graduated preset intervals of elapsed time, excess velocity, or minimum altitude, if the skydiver does not deactivate or disengage it during normal descent.
apex :: The center and topmost point on the crown of a round or domed parachute canopy. Also, area at the top of a hang glider's triangular control bar.
apex vent :: A circular hole introduced at the uppermost point in the crown of a round or dome-shaped parachute canopy, which air flow will eliminate oscillations without markedly increasing the descent rate; a design feature initiated by Joseph Lelandes, a French scientist, in 1804.
apparent wind :: The wind perceived by an observer; also known as 'relative wind' (qv).
approach :: The positioning of an aerodynamic body on the glide path planned for its final approach to landing; aircraft are generally required to obtain clearance and to use either visual aids or electronic beacons in this flight phase. [cf: volplane]
apron :: The cleared area, usually paved, near an airfield's buildings, hangars, and airstrips where planes are parked for the loading of personnel and cargo; may also be used as a staging or maintenance area. Also called a "ramp".
arch :: A neutral body position of hips thrust and back bent so the shoulders and knees are level, with head up and arms back, that skydivers use to orient the front of their torso toward the relative wind.
ARD :: Automatic Release Device, as used when towing (eg: para-sail, glider, etc).
area :: See wing area.
ARP :: The Aerial Release Point determined by pre-flight or in-flight mission planning for an airdrop.
arrow :: Slang for the body posture commonly called 'delta' (qv).
ARSA :: The abbreviation for Airport Radar Service Area.
artistic events :: Competitive skydiving events that include freestyle skydiving, freeflying, and skysurfing; also known as aerobatics.
ascending parachute :: A parachute capable of upward and lateral movement, as well as descent, as a result of the wind or air pressure directed at the canopy or airfoil from a portable device by the suspended parachutist. Due to its pilotage, the ascending parachute could be classified as a type of ultralight aircraft.
ASI :: The Abbreviation for AirSpeed Indicator.
ASP :: Accelerated Skydiving Program; a form of Accelerated Free Fall (AFF) practiced in the Southwestern USA that includes two tandem jumps and an enhanced version of the USPA AFF syllabus.
aspect ratio :: The ratio of a square canopy's width (side to side) to breadth (front to back). Seven cell canopies typically have an aspect ratio of about 2.2 to one, while nine cell canopies are usually between 2.8 and 3.0 to one. A short-aspect ratio airfoil maneuvers better while a high-aspect ratio airfoil soars and glides better.
assistor pocket :: Air scoops situated at the top of a sleeve, which provide drag and aid in anchoring the sleeve as the canopy is pulled out. Also, fabric pockets on the bridle of a free bag, which aid in the deployment of the bag in the event of a horseshoe-type malfunction.
ASTRA :: A "fail-safe" Automatic Activation / Opening Device (AAD/AOD) made by FXC Corporation.
atmospheric pressure :: The normal amount of pressure exerted by the earth's atmosphere, being 14.7 pounds per square inch (called "one atmosphere") at sea level; also known as "barometric pressure". [nb: atmospheric pressure is typically halved at 18,000ft above sea level]
attitude :: The orientation of an aerodynamic body in the pitch, roll, or yaw axes; the body position (qv) of a freefalling parachutist.
audible altimeter :: An alarm used by skydivers to alert them about reaching one or more pre-set altitudes, as used by videographers and freestylists (who cannot visually check the display of an altimeter); may be coupled with an Automatic Activation / Opening Device (AAD/AOD).
auger :: To land at unsurvivable speed; also called "bounce", "pancake", "frap", "hammered", and "go in".
autogiro :: Formerly a trademark for a 'gyroplane' (qv).
Automatic Activation Device :: Abbreviated AAD (qv); also known as Automatic Opening Device (AOD).
Automatic Opening Device :: Abbreviated AOD (qv); also known as Automatic Activation Device (AAD).
Automatic Release Device :: A self-contained mechanical release system attached to a tow-bar in a para-sail harness configuration (flexible or ridged), which disconnects the towline from the canopy when activated, releasing the para-sailor; abbreviated ARD.
auto-rotate :: The unpowered controlled descent of an aircraft by decelerating gravity and dissipating lift through horizontal prop free rotation along a nonaerodynamic glide path; also called "spin-in". [cf: volplane]
auxiliary :: Synonym for a reserve parachute, especially on a tandem harness.
backslide :: To move backward in freefall relative to a fixed or neutral reference; usually caused by poor body position, and often unintended and undesired.
backwash :: The portion of the wash of an aircraft that flows to the rear.
bag :: The deployment bag into which the canopy is packed; sometimes called a "sleeve" or "pack sack", it helps to ensure proper release, and helps to prevent abrasion.
bag lock :: A malfunction of a deploying parachute wherein the canopy remains in the deployment bag.
balloon :: So-called for its resemblance to a ball, a large bag, of coated or zero-permeability fabric, of non-porous or other synthetic material, that's filled with heated air or a gas lighter than air, which is designed to rise and float, often with a gondola suspended under it for passengers or instruments; when free flying, balloons drift with the wind, although the altitude can normally be controlled either by heating the air or by releasing ballast ... greater directional control has been obtained in tests using an experimental wing-shaped balloon. [nb: because the wind direction changes with altitude, a balloon can attain some directional control by changing its altitude] [nb: first successful manned flight of hot-air balloon by Joseph-Michael and Jacques-Etienne Montgolfier (1783)]
ballute :: Made from a high temperature, silicone-ceramic wire mesh for hypersonic deployments, the ballute has been constructed from thin plastic for high altitude and low speed deployments, which inflates quickly and uniformly on drag loads of 500-1000 pounds, and at speeds of Mach 3-6, wherein the weight and volume limits of the ballute is greater than a comparable hyperflo parachute. Designed for high altitude deployment by Goodyear, this ram-air (four ramair scoops) parachute includes a toroidal shaped burble fence at the meridian of the bag, ensuring that the flow separates uniformly, which eliminates any destabilizing forces caused by irregular vortex shedding. The skirt of the parachute is narrower than the equator, so causes the air to collapse uniformly into the low pressure area behind the body; the inverted conical shape in front of the burble fence also helps to stabilize the parachute. A ballute parachute was used on the Gemini back-up ejection seat (max@ Mach 4 at 80,000 feet), and also used as a descent retarder for the Mk-82 bomb. [nb: at 720# drag load, the opening force coefficient is 1.93 for a 5.5 ft diameter ballute at Mach 2.6 and dynamic pressure of 220 PSF, the drag coefficient has a maximum of 1.2 at Mach 1.0 in a progressively inverse ratio]
Barish sailwing :: See sailwing.
barometric pressure :: Atmospheric pressure affected by weather, as measured by an aneroid barometer, wherein standard atmospheric pressure has a value that's equivalent to the pressure exerted by a column of mercury 29.92 inches (760 mm) high, or 1013 millibars (101.3 kilopascals). [nb: atmospheric pressure is typically halved at 18,000ft above sea level]
base :: The core around which a freefall formation of skydivers is built, which can be a single person or a group of people, depending on the shape of the formation and the number of skydivers involved. Such an initial target is also the focus for building a canopy formation.
BASE jump / B.A.S.E. jump :: A parachute jump made from a fixed object as a launch platform, instead of an aircraft; the acronym represents these fixed objects, such as a Building, Antenna (tower), (bridge) Span, or Earth (cliff), and includes tethered balloon jumps. Because BASE jumping does not conform to the legal definition of parachuting (ie: "descent of an object to the surface from an aircraft in flight"), it is not addressed by the USPA nor regulated by the FAA.
base leg :: That portion of the three-legged landing pattern wherein the jumper flies across the direction of the wind, downwind of the landing area, before turning into the wind for final approach toward the target.
base tube :: The lower component in a triangular framework known as a 'control bar', which is connected to angled vertical down tubes at the sides of a hang glider; a specially curved version ('speed bar') improves comfort and mobility over the straight base tube.
basic :: The novice rating for military parachutists requiring ground training and a minimum of five static line jumps (one with full equipment and one at night), which qualification is oriented to vertical tactical operations.
Basic Safety Requirements :: See BSR.
baton :: In competition skydiving, a thin cylinder that's used as a distinctive marker when being passed from one freefaller to another on an airborne relay team.
batten :: The structural ribbing that forms the shape of the flexible sail on a hang glider or similar airfoil.
bean bag :: See shot bag. [cf: Hacky Sack®]
Beaver :: DeHavilland L-20 / U-6 fixed-wing "bush" aircraft, STOL capable by wheels, skis, or floats.
Beech :: Informal reference to Beechcraft, an airplane manufacturer established by Walter Beech with headquarters in Kansas, producer of the Twin Beech (D-18) used as a jump plane.
belly-band / bellyband :: An additional harness strap crossing the jumper's abdomen that is typically found on older para-rigs, or emplaced on student rigs for gripping with the "harness hold" method of AFF. Also may be used as a pilot chute pouch location for throw-out deployments.
belly flying :: See flat flying.
B4 / B-4 :: See flight bag.
BIC :: The Basic Instructor's Course introduces experienced parachutists to the essential methods for safely teaching new students.
birdman :: An aviator, or anyone associated with aircraft or flying; also known as pilot, jet jock, airdale, zoomie, and rotor head.
black hat :: A black-colored baseball-style cap worn by US Army Infantry school instructors of airborne techniques. Similar cap affixed with "winged torch" device adopted by US Army Pathfinders.
blast :: Slang for a parachute jump; probably derived from the definition of a violent gust or forcible stream of air. Also, the unique initiation ceremony ("prop blast"), often ridiculously ritualized and rowdy, that celebrates the qualification of new skydivers or the assignment of novice paratroopers to their first airborne unit.
B license :: The second-level rating from the U.S. Parachute Association (USPA) signifying that a skydiver is able to perform night jumps, to participate in collegiate 4-way formations, and to apply for a coach rating; the license of physically impaired skydivers may be restricted (B####R) to ensure safety.
blimp :: slang for any small nonrigid airship, dirigible, or balloon, as used for observation, training, or transport; also called sausage or gas bag.
BLOB :: The abbreviation for Big Lump On-Board, being an observer; any extra person or noncontributing passenger.
blocks :: See dive blocks.
blow-out :: The abrupt failure of a canopy panel or cell, which is most often due to excessive wing loading (qv), but may also result from wind gusts, inclement weather, penetration by foreign object or falling body, fabric abrasion or fatigue. A blow-out can cause the entire canopy to fail as a decelerator.
blue skies :: A salutation or valediction among sport parachutists and freefallers, based upon a civilian interpretation of appropriate conditions for jumping. Military parachutists jump at night, in foul weather, and with field or combat gear, so they prefer the safer "clear skies"!
blue thermal :: A thermal that is not marked by a characteristic cumulus cloud.
BOC :: Bottom Of Container; refers to the location of the pilot chute, normally secured in a Spandex pouch, for hand deployment; as opposed to belly (belly-band) or leg (ROL) mounted, and much less vulnerable for the bridle.
body English :: Slang for the body positions, postures, and/or attitudes that're assumed by a maneuvering skydiver, parachutist, or hang-glider, as when aerobatically turning or recovering from a malfunction.
body harness :: The configuration of adjustable webbing straps (retaining legs, shoulders, chest and/or waist) that're used to secure a parachute container or pack (and its contents) to a person's body; the flexible harness used in para-sailing is also attached to the towline tether by a tow-bar, and is distinguished from the ridged para-sail gondola, which holds one or more persons in a seat that's directly connected to the para-sail canopy.
body position :: Ones freefall body posture; also called "attitude". Variations in stable body position (eg: track, delta, frog, de-arch, box man, spread eagle, funnel) make the wide range of freefall maneuvers possible for elements at different fall rates. [nb: persons who lose their stable posture through inexperience or injury when falling, and who remain conscious, are usually unable to recover stability and tend to incur a malfunction when they deploy their parachute; a conscious person falling without a parachute has a tendency to stabilize in a horizontal posture, landing either prone or supine; but an unconscious person falling without restraint has a tendency to fall vertically, landing head-first; however, a suicide who elects to jump to his death generally tends to fall vertically, landing in a feet-first upright posture (only a few suicides deliberately fall head-first; those not landing vertically tend to windmill)]
bomber :: Slang for the body posture commonly called 'frog' (qv).
bonus day club :: An informal and unofficial association of individuals who qualify for membership by surviving a near death episode, such that their personal life-calendar re-starts at day one by sheer good luck or divine providence ... "this is the first day of the rest of your life". Probably the most dramatic episodes experienced by club members involve freefalling without a parachute, but others, such as shipwreck or vehicle accident survivors, involve "riding the wreckage", because the odds of survival significantly improve when the bereft victim is not completely naked ... although a few have miraculously survived that exposure as well. [nb: thirty-one chuteless freefallers have survived with wreckage versus thirteen who have survived without wreckage since 1940; as compared with the deaths of more than 119,000 people in aviation mishaps, including failed-chute skydivers, for the same period]
boogie :: Slang for a gathering of skydivers, usually focused on fun rather than competition; usage adopted in the 1970s from the word for indulging in a good time or getting carried away with playful activities (eg: "Let's boogie!"). Major drop zones host several boogies each year, often on long holiday weekends.
boomer :: Slang for a strong thermal.
bounce :: To land at unsurvivable speed; also called "auger", "pancake", "frap", "hammered", and "go in".
box man :: A neutral, face-to-earth body position in which the arms form right angles at shoulder and elbow, and the legs are spread at about 45 degrees from the long axis and bent 45 degrees at the knees. Generally considered the ideal position for formation skydiving.
brakes :: The steering controls of a ram-air parachute. The brake lines of the square canopy are synonymous with steering lines. When used together, they slow the parachute; and when used independently, they result in a turn. The position of the parachute steering controls, measured in relative increments (eg: quarter brakes, deep brakes, etc), are used to control speed and descent during stable flight.
brake turn / braked turn :: An open canopy turn that reduces the loss of altitude by first slowing forward speed and then, by adjusting the steering toggles, allowing one side of the canopy to fly slightly faster, which effect will change the parachute's heading. Such a prolongation of turns and traverses can be dramatic when performed in sequence, as by a club or at a boogie.
breakaway :: Alternate term for "cut-away"; usage discouraged, since it may be confused with 'break off'.
break off / break-off / breakoff :: To interrupt, discontinue, or cease formation skydiving prior to chute deployment by tracking away from the formation; not the same as "breakaway". Also refers to the pre-arranged altitude, called "break off altitude", at which level of agreed height, skydivers disconnect their formation and move to a clear space before canopy deployment. Similarly refers to the pre-arranged altitude at which no other incoming canopies can dock onto a CRW / CFS formation.
break off altitude :: The pre-determined altitude at which individual skydivers separate from their formation so as to safely deploy their parachutes, or separate from a canopy formation so as to begin their individual landing procedures.
bridle :: Part of the deployment system, being the thin webbing strap or tape running from the pilot chute to the top of the main canopy or deployment bag.
Bronco :: North American OV-10 short take-off and landing (STOL) fixed-wing aircraft.
BSR :: Basic Safety Requirements. BSRs are USPA guidelines, which are regarded as excellent minimum safety standards for self-governing skydiving activities, but lack the force of law.
B-12s :: Clip hardware that's sometimes used for leg-strap attachment on a parachute harness; as derived from the MS 22044 hardware that was originally used on the U.S. Army B-12 parachute assembly.
bump :: A severe upward thrust given to a flying object by a rapidly rising current of air.
bundle :: Slang for a number of distinct items packaged together and delivered at the same time, as by para-drop.
Bungee® :: See shock cord.
burble :: The area of turbulence behind an object (wash, wake, or backwash) generated by going through the air, whether a person in freefall or a canopy / airfoil in flight.
buttonhook :: A swiftly executed pirouette-like sharp reversal; to quickly change the direction of movement by 180 degrees, as when suddenly reversing the flight of a parachute canopy immediately before landing; derived as an extension of the sports metaphor (running a reversal on a playing field) from the metal hook used in the 19th century to pull buttons through a tight buttonhole on clothing and footwear. [nb: not to be confused with a 'dynamic stall']
call :: The time remaining until a stick can board the aircraft.
camber :: A convex arch, especially the central rise of the curve of an airfoil, usually expressed as a ratio of the curving rise to the length of the airfoil's chord.
cannonball :: Slang for the body posture commonly called 'frog' (qv).
canopy :: A "deployable aerodynamic decelerator" constituting the principal element of the parachute; this shaped construction of fabric and suspension lines is used to safely descend and land during parachuting, often used in conjunction with a clarifying type reference (eg: round, square, zero-p, main, or reserve). The typical canopy consists of fabric membranes that connect to the parachute harness by suspension lines, which provide the means for the jumper to safely descend. Although parachute canopies were first made of canvas, silk proved to be better suited because it was thinner, stronger, lighter weight, easier to fold (and unfold), more resilient, and fire resistant. When silk became unattainable during World War II, parachute manufacturers began using nylon fabric, which proved to be superior because it was more elastic, more resistant to mildew, and less expensive. Parachutes made of 'ripstop' nylon is woven with a double or extra-thick thread at regular intervals, creating a pattern of small squares, which structure keeps small tears from spreading. Nylon is also used to fabricate other components (eg: reinforcing tape, harness straps, and suspension lines), but other fabrics (ie: Dacron polyester, Kevlar para-aramid fiber) have been used in recent times.
canopy formation :: A competition involving the building of opened canopies into a formation, as regulated by the Federation Aeronautique Internationale (FAI).
canopy formation skydiving :: The term formerly known as "Canopy Relative Work" (CRW); abbreviated as "CFS".
canopy relative work :: The term formerly used to describe "Canopy Formation Skydiving" (CFS); abbreviated "CRW". The intentional maneuvering of two or more open parachute canopies in proximity to or in contact with one another during descent.
canopy release :: A device (ie: Capewell / Chrysalis / three ring release / clutch release) which allows immediate separation of the parachute risers, suspension lines, and canopy from the harness; this precaution is undertaken to avoid fouling a deploying reserve on an existing main canopy malfunction. [nb: Capewell Canopy Release device was designed and developed by CW4 John Ashley Ward; three ring canopy release system was invented by Bill Booth]
Caravan :: (forthcoming) economical fuel but high maintenance, with large door for 14-16 skydivers on a jump run
Caribou :: A lightweight, small-capacity, twin-engine, short take-off and landing (STOL) transport aircraft (CV-2 / C-7A); nicknamed "bou" / 'bou.
CARP :: The Computed Air Release Point calculated by mission planning software for an airdrop.
CASA C-212 :: A twin turbine-powered medium short take-off and landing (STOL) transport aircraft manufactured by Construcciones Aeronauticas SA since 1974; this jump ship climbs quickly, carries 28-32 skydivers on a jump run, and has a large tailgate exit ramp.
cascade :: At the point where two suspension lines join together, an arrangement for running them smoothly into one, which results in reduced bulk and drag.
CAVU :: Acronym for 'Clear Air, Visibility Unlimited'.
ceiling :: the height above ground level of the lowest layer of clouds that cover more than half of the sky. Also, the maximum altitude at which an aircraft can operate under specified conditions. Also, the maximum altitude from which the surface of the earth can be seen from an aircraft in flight.
cell :: A chordwise sectional pocket, similar in function to a panel, situated in a parachute canopy. Square or ram-air canopies are composed of pressurized cells, usually consisting of seven or nine cells in an area from about 70 square feet to over 300 square feet. Each cell consists of a load-bearing rib at each side to which the suspension lines are attached. A third, non-load-bearing rib runs down the middle of the cell, but an individual celll may be split into more than two parts. The cell is pressurized through the opening (mouth) at the front, and also through cross ports in the ribs. Adjacent cells share load-bearing ribs. In general usage, a 'cell' is any portion of a canopy separated by vertical ribs. Canopies with more cells generally have more ribs and more fabric, so they are not as small and compact as parachutes with fewer cells when packed.
center lines :: Referent for the suspension lines extending from the apex to the skirt of the canopy, whereupon they continue to the risers.
center of pressure :: An imaginary point on the chord of an airfoil where the totality of all aerodynamic forces are assumed to act.
center point :: The basis point around which freefall movement takes place. In an individual the center point is considered to be in the middle of the torso. In a group, it is the base point that the formation centers around. In an airfoil, it is the balance point (or 'center of gravity') wherein the pilot controls a glider or sailplane in flight.
Centurion :: Cessna P-210 single-engined light transport airplane with a pressurized cabin.
certificated :: Indicates the FAA-approval status of parachute components. [nb: this term has been (ungrammatically) extended to parachute riggers and aircraft pilots, who are properly 'certified']
Cessna 182 :: (forthcoming) 4 skydivers on a jump run
Cessna 205 :: (forthcoming) 5 skydivers on a jump run
Cessna 206 :: (forthcoming) 6 skydivers on a jump run
Cessna 207 :: (forthcoming) 7-8 skydivers on a jump run
Cessna 310 :: Twin-engined, low-wing monoplane featuring nose storage and swept-back vertical tail surfaces as made by Cessna (L-27/U-3) for light utility, communications, and administrative support from 1954 to 1980; nicknamed "blue canoe". [v: Turbo 310, Turbo 320 Skyknight]
CFS :: Canopy Formation Skydiving; formerly known as "Canopy Relative Work" (CRW). CFS involves flying open canopies in close formation, where the pilots grip each other's parachutes to form patterns, often geometric.
CG :: The abbreviation for Center of Gravity, being the balance point wherein the pilot controls a glider or sailplane in flight.
chalk :: The file of airlift infantry which conforms to the size of the transport aircraft, regardless of their regular table of organization and equipment (TO&E) assignment; as derived from temporary group assignment numbers chalked onto the helicopter hulls.
chalk commander :: The qualified individual who is responsible for and in control of the group of troops embarked under the same chalk number; sometimes called "mother hen".
chalk number :: The number designating the transport carrier and its complete load of men and materiel.
check of threes :: A pre-jump self-check of equipment that's performed in the aircraft; including check of "three-ring" release system (or other RSL) for correct assembly; check three points of harness attachment for snap assembly or correct routing and adjustment; check positioning of three operational handles -- main canopy activation, cut-away, and reserve.
cherry blast :: Slang for someone's first parachute jump, whether civilian or military; performed by a trainee after completing ground school. Also, a paratrooper's first jump with an assigned airborne unit after finishing jump school training; being the sixth jump for soldiers, and the eleventh jump for Marines.
Chinook :: The large, twin-engined Boeing transport or cargo helicopter (CH-47) that's been operational since 1962; its 90ft fuselage includes a rear loading ramp and side access doors; also called 'hook, "shit hook", or "Flying Oscar" (after the Oscar Meyer wiener) ... serving 45 skydivers on a jump run. [nb: 'Sea Knight' (CH-46) is the USN/USMC amphibious version (nicknamed "frog") of the Chinook]
chord :: The longest front-to-back dimension of a wing at any given point along its span; also called "chord line", as an imaginary straight line connecting the leading and trailing edges of an airfoil cross-section. The chord is the reference used to determine the angle of attack, and to draw lift, weight, and other vectors when analyzing a wing that is producing lift.
chute / 'chute :: Short form of 'parachute', as to descend in a 'chute.
chute assis :: The French term for 'sit flying', or the freefalling body position of presenting one's seat to the relative wind.
chutist :: Short form of 'parachutist'.
cleared :: Designates the passage, by authorized signature(s), of any qualified student to advancement, including supervised current re-certification.
C license :: The third-level rating from the U.S. Parachute Association (USPA) signifying that a skydiver is able to participate in intermediate-altitude jumps, to perform open field and level one exhibition jumps, to accompany (as an observer) tandem instructor rating renewal and training jumps, and to apply for SL, AFF, and IAD Instructor ratings; the license of physically impaired skydivers may be restricted (C####R) to ensure safety.
climb-out / climb out :: The positioning of a jumper(s) in or near the door, or on protuberances or structures outside the aircraft in preparation for either a "poised exit" or a group launch at the jump spot.
closing loop :: The small lace that, once threaded through the container eyelets and locked with a closing pin, holds the container flaps closed around the parachute canopy until activation releases the retainer pin and guided loop for deployment.
cloud base :: The altitude at the ceiling on the underside of a cloud layer.
cloud street :: When a steady wind is present, thermals and their respective cumulus clouds (formed by the rising air in a thermal as it ascends and cools, until the water vapor in the air begins to condense into visible droplets in the lower atmosphere) can align in rows oriented with the wind direction, which apparent lanes denote a lift avenue for soaring.
clutch / cut-away clutch :: Slang for the single "cut-away release handle", which disconnects a malfunctioned main canopy by the simultaneous release of the riser connections to the harness. If either a reserve static line (RSL) or a single operation system (SOS) is connected to the clutch, then the jumper's reserve chute will be automatically deployed; otherwise, once clear of the main, the reserve must be initiated by the jumper.
coach :: A parachutist with some formal training in the art of instructing freefall techniques; also known as "jumpmaster" and "monitor". The USPA-rated coach may teach the general or non-method-specific sections of the first-jump course, and conduct individual or group freefall skills training and jumps with entry-level students, under the supervision of an USPA-rated instructor.
cocoon :: Informal reference to the soaring harness that encloses and supports a glider pilot from shoulders to toes.
collapsible pilot chute :: A hand-deployed pilot chute that automatically collapses after deploying the main canopy.
collapsible slider :: A slider (qv) rigged so that the jumper can compress or wrap it so as to reduce drag.
connector links :: The method of attaching the parachute's suspension lines to the top of the risers; which are also known as "rapid links".
container :: The element of the parachute that houses the canopy and its attachments; that portion of the parachute system that closes around the folded parachute canopy and its deployment device so as to secure and store it until deployment. More properly known as the "harness/container", this element is designated "pack" by the FAA.
control bar :: The triangular framework that a pilot uses to launch, land, and control a hang glider, comprising a base tube at the bottom and angled vertical down tubes at the sides.
controlled airspace :: An area, marked on air sectional charts, in which services to pilots are provided by the Federal Aviation Administration (FAA).
Cooper vane :: A wind-activated safety latch (ie: mechanical aerodynamic wedge) that prevents the opening of a personnel hatch or cargo ramp while a civilian airplane (eg: Boeing 727, Douglas DC-9, etc) is in flight; also called a "Cooper switch" or "Cooper device", this precaution was introduced after D.B. Cooper hijacked a airliner in 1971, escaping with the $200,000 ransom by parachuting from the tailgate at a 10,000ft altitude over southwestern Washington state ... he was never apprehended.
Coriolis effect :: The deflection (Coriolis force) of a body in motion as caused by the earth's rotation; eponymously after Gaspard G. Coriolis. [v: precession]
cork :: Slang for the conspicuously rapid deceleration of a skydiver who loses control during high speed formation freefall; analogous to "pop up" / "pop out" like a cork. Slang for the loss of control during high-speed group freefall maneuvers, resulting in rapid deceleration and obvious displacement.
cotter / cotter pin :: A pin or wedge that's inserted into an opening so as to secure something in place or to hold parts together, often employing some mechanism to prevent it from working loose.
crabbing :: When a canopy moves crabwise; to fly a canopy at an angle to the ambient wind, resulting in an oblique path across the ground that is sideways as well as forwards, so as to counteract drift deflection.
creep :: To practice freefall formation sequences while laying prone on a wheeled creeper in a level open area, such as on an armory floor or a paved parking lot.
creeper :: A low torso-sized board, mounted on casters, used by mechanics for easy access beneath or below objects, which may be used by skydivers to simulate freefall formation maneuvers.
crew chief :: The senior crewmember who is responsible for the care and maintenance of an aircraft; in the military, this duty is differentiated from both loadmaster and jumpmaster.
crew dog :: Slang for any aircraft crewmember.
critical angle :: The angle of attack at which a sudden change in airflow occurs around the wings or other airfoil, reducing lift and increasing drag; can result in a stall.
crossbars :: Main structural members that run between the keel of a glider and its leading edges; these are concealed within the sail on double-surface gliders.
cross braced :: Descriptive of a canopy designed with longitudinal trussing between the vertical ribs so as to flatten and stiffen the wing in flight.
cross connectors :: Straps attached between the risers, from front to rear, as used for canopy formation. These straps are intended to prevent the docked jumper from sliding back up the lines, which is especially important for plane formations. Also used with some reserve static line (RSL) systems, where they are attached from side to side to prevent premature reserve deployment when only one main canopy riser is released during a cut-away.
cross-controlling :: The practice by inexperienced pilots of counteracting their intentions by contrary postures or exaggerated positions, such that incorrect techniques cancel one another, making sustained airfoil flight hazardous.
cross ports / crossports :: Vent holes in the structural ribs of a cell that equalizes air pressure by allowing air to flow from one cell to another; equalization vents situated between canopy cells so as to stabilize a ram-air parachute in flight.
crosswind :: A path perpendicular to the direction of the wind. Also, a prevailing wind that crosses the direction of movement.
crown :: The top or uppermost portion of a parabolic canopy, as from the apex to its equator; steering and stability vents are generally inserted below this area.
CRW :: Canopy Relative Work; now officially known as "Canopy Formation Skydiving" (CFS). CRW involves flying open canopies in close formation, where the pilots grip each other's parachutes to form patterns, often geometric. Sometimes pronounced "CReW" as an acronym instead of 'C R W' as separate letters.
cumulus :: A class of clouds characterized by dense individual elements in the form of puffs, piles, or towers, with flat bases and mounded tops; often indicative of thermal lift.
cumulonimbus / cumulo-nimbus :: An anvil-shaped cloud indicative of thunderstorm conditions, characterized by large, dense towers that may penetrate the upper limits of the troposphere.
cup :: Slang for de-arch (qv).
cupid :: Slang for altitude expressed in hundreds of feet above ground level (AGL).
current :: Sufficiently recent participation or practice in parachuting that neither refreshment nor supervision is required for safe conformance; any interruption in jumping of a year or more should be renewed, if not formally re-certified, to bring skills up to date.
cut-away / cut away :: The act of disconnecting or releasing the main parachute canopy; also known as "breakaway". In the event of a total main canopy malfunction, a parachutist must eliminate the obstruction before deploying the reserve parachute, or the new canopy will become entangled with the old, and the parachutist will fall to his death. A cut-away is the standard emergency procedure implemented prior to deploying the reserve chute. The manual method of disconnecting the canopy risers from the harness at the Capewell / Chrysalis / three ring release junctures was superseded by a simple clutch release system activated by pulling a single handle. The cut-away and reserve deployment sequence is linked in tandem rigs. This method of canopy release is also used if open canopies become inextricably entangled, or if ground speed after landing is hazardous enough to drag the parachutist.
cut-away clutch :: see clutch.
cut-away handle :: A single handle, usually mounted on the harness, used to release both main risers simultaneously; also known as the "clutch", "cut-away release handle", or "single point release", and includes the patented "three ring" release.
CYPRES :: A type of "fail-safe" Automatic Activation / Opening Device (AAD/AOD), made in Germany by AirTech; this is the most common type, and the first modern design to be widely adopted by expert skydivers.
Dacron® :: A brand of polyester fiber that's commonly used as a resilient construction material for canopy suspension lines, which are often thicker and softer than so-called "microlines" made of Spectra. Also, a polyester fabric used to make the flexible wing on gliders and other airfoils.
Dakota :: The Douglas DC-3 (C-47) twin-engine, fixed-wing light transport aircraft, which revolutionized air travel in the late 1930s and continues to be a reliable aerial platform for the next 75 years; also called Gooney Bird, Night Train, and Sky Train while flying airdrop, tow plane, medevac, and gunship missions for the military ... serving 45 skydivers on a jump run.
damp / dampen :: To check, retard, or deaden the action of an airfoil in flight; to counter, resist, or offset the change in motion or direction of a canopy or wing.
dart :: Slang for the body posture commonly called 'delta' (qv).
data card :: A data card of basic information about the reserve parachute (ie: type, serial number, date last packed, owner, etc.) that must accompany every chute in each rig or deployment; also called 'packing data card'.
D-bag :: See deployment bag.
dead spider :: Slang for de-arch (qv).
de-arch :: To flatten out or reverse one's body position from the normal arched box man; also known as "dead spider", "hump", "hollow", and "cup". A de-arch body posture results in a slower fall rate than an arch.
decision altitude :: The altitude at which a skydiver is trained to begin executing emergency procedures; usually 2,500 feet AGL for students, 1,800 feet AGL for civilian skydivers, and 1,200 feet AGL for military freefall parachutists. The pilot of the jump plane must be informed of both the jump altitude and decision altitude before take-off.
delta :: A rigid, face-to-earth body position in which the entire body resembles an acute isosceles triangle, with arms and legs extended with the torso in a straight or level plane. The legs are spread about shoulder width, with toes pointed. The arms may be overhead, as in a swimmer's dive, or beside the torso, as in a sailor's dive. This low-profile posture, which is also called "arrow" or "dart", results in the most rapid descent possible for a skydiver.
demo :: Short for demonstration jump (qv).
demonstration jump :: Any exhibition or performance jump made away from an established drop zone (DZ) for the benefit of spectators; also called "demo".
density altitude :: An expression of air density relative to standard atmospheric pressure at sea level (MSL), which is achieved by determining the temperature and elevation of the landing field, then comparing the result with an equivalent sea level altitude at standard temperature; this expression has a bearing on the load capacity and lift capability of the subject aircraft.
deployment :: That operational interval, or portion of the parachute opening sequence, from the moment of container (or pilot chute) release to the moment of suspension line stretch, but before the canopy fully inflates; also called "development".
deployment bag :: A sleeve that retains the parachute canopy until the suspension lines have deployed; more commonly called a "bag" or "pack sack". A pilot chute lifts the deployment bag away from the parachute container so the suspension lines will extend in proper array before the canopy emerges. This bag serves to control or regulate the parachute's opening progression.
deployment device :: An intermediate container, usually a bag (D-bag or pack sack), that contains or constricts the folded parachute through complete suspension line deployment.
deployment system :: The components of the parachute that control deployment of the canopy, including pilot chute, bridle, and bag.
development :: See deployment.
diaper :: A type of deployment device consisting of a fabric panel, similar to a slider, attached near the lower part of a canopy, which prevents canopy inflation until the suspension lines are fully stretch; used frequently with round parachutes to reduce opening shock and high speed malfunctions.
dihedral :: The angle at which the wings of an aircraft are vertically inclined, as formed by two planes (dihedron); the upward angling of wing tips to make an aircraft more stable during a roll.
dingleberry :: Slang for a gear bag or equipment pack that's released for suspension by a tether or guy rope, called a "lowering line", from the harness of a paratrooper after the canopy has properly deployed; also called "dangleberry" or "dillberry". Just as the retaining straps on weapons are released from the jumper's leg, likewise this kit bag is let down so as not to injure or interfere with the paratrooper safely executing a parachute landing fall (PLF).
direct supervision :: The legal responsibility assumed by someone in authority for the knowledge and performance of a direct subordinate, which oversight normally takes place in the immediate presence of that supervisor, such as teaching a specific skydiving technique or packing a parachute. [nb: authority can be delegated, not the responsibility for that authority]
dirt dive :: To rehearse a skydive on the ground by walking through the positions and stations; usually preliminary to or instead of creeping through the formation.
dive blocks :: Handholds or hand grips (not loops) on the front risers to facilitate steering the canopy into a dive; also called "blocks" or "grabs".
dive floater :: A skydiver who is inside the airplane in the exit line up, but leaves prior to the base. This configuration only occurs on large freefall formations.
dive loops :: Many advanced skydivers have modified their front risers by the addition of "handles" or "grab loops" to make it easier for them to grip the front risers when steering into a dive; also called "blocks" or "front riser loops".
diver / 'diver :: A skydiver; a freefall parachutist.
diver exit :: Headlong departure from an aircraft without pre-positioning or bracing to achieve a stable entry into the airstream; also called "door exit".
divergence :: The tendency of an aircraft, glider, or other airfoil to increase the steepness of its dive, which indicates a dangerous lack of pitch stability.
D license :: The highest-level rating from the U.S. Parachute Association (USPA) signifying that a skydiver is able to participate in high-altitude jumps, to participate in national competitions, to perform supervisory or examiner functions, and able to apply for all instructional and proficiency ratings; the license of physically impaired skydivers may be restricted (D####R) to ensure safety.
dock :: To make controlled physical contact with another skydiver while in freefall; or, when building canopy formations, with another jumper's open canopy.
door exit :: See diver exit.
door jam :: To practice exit procedures in the mock door of a simulator as part of ground training, or in the door of a mocked-up aircraft of a particular type prior to a formation skydive.
dope on a rope :: An unflattering catch-phrase for a static line parachutist.
double-surface :: A glider with upper and lower sail surfaces that enclose the airframe so as to reduce drag and improve performance.
downdraft :: A descending flow or current of air, especially a thermal inversion caused by a cooling surface or an aperture in the earth's topography.
down plane :: A CRW/CFS formation with two canopies, both pointed toward the ground. This can also occur with a single skydiver with both main and reserve chutes deployed.
down tube :: One of the angled vertical side elements in a triangular framework known as a 'control bar', which is connected to a base tube at the bottom of a hang glider.
downwind :: In, on, or toward the direction the wind is blowing; or positioned farther along the wind's path. Also, a landing facing downwind.
downwind leg :: That portion of the landing approach flown with the wind blowing from behind the jumper.
drag :: The aerodynamic force exerted upon an airfoil, wing, or other aerodynamic body that tends to reduce its forward motion; a mechanism that permits greater vertical maneuvering without increasing the flight's rate of speed.
DRCP :: Dummy Rip-Cord Pull. In civilian static line training, the student demonstrates self-deployment by simulating a rip-cord pull from a stable body position before (within four seconds) the main is automatically released by a static line. Standard practice is to jump the student five times by static line, with four successful DRCPs, before the student is allowed to freefall solo for the first time. Also called "practice deployment".
D-ring :: The handle used to manually release the rip-cord when deploying a parachute for descent.
drive slots :: The vent openings situated in the back of a gliding parachute canopy through which air is expelled, providing forward speed and stability during descent; the configuration of these vents determines whether a canopy is a high or low wind chute.
drogue :: A pilot parachute that functions to extract the main parachute from its container after the static line or rip-cord has opened the pack sack. May also refer to the throw-out pilot parachute, which functions identically. [v: pullout]
drogue fall / droguefall :: In tandem skydiving, the portion of the descent where a drogue has been deployed between freefall and main parachute deployment; this trailing drag device is used to retard the movement of an object through the air, so as to regulate the fall rate of tandem skydivers.
dropmaster :: An individual qualified to prepare, perform acceptance inspection, load, lash, and eject material for airdrop. Also, an aircrew member who, during parachute operations, will relay any required information between pilot and jumpmaster.
dropsonde :: A type of meteorological radiosonde that's hand-sized and parachute-equipped so as to collect atmospheric measurements (eg: altitude, temperature, humidity, barometric pressure, wind speed, wind direction, etc) that's transmitted to the mission planning computer for real-time updates; a sophisticated wind drift indicator (WDI) that's hand-launched from the jump plane so as to properly calculate the jump spot.
drop zone :: The specified landing area for parachutists; commonly designated "DZ", and also known as "pit" or "jump target". May also refer to the place where parachute operations are conducted, such as a large or commercial skydiving center (ie: sanctioned drop zone). A drop zone is any pre-determined area upon which parachutists or air-delivered objects land after making an intentional parachute jump or airdrop, which is specified by reference to the nearest VOR broadcast station (when closer than 30 nautical miles), or to the nearest town or airport (when farther than 30 nautical miles).
dual assembly :: A two-canopy parachute system, also known as a tandem rig; includes the main and reserve canopies, harness and container system, and all other components.
dummy rip-cord pull :: See DRCP.
dynamic stall :: The pivoting or pendulum action of the suspended load (ie: the parachutist) that's initiated when the braking flare of a ram-air canopy causes the load to swing forward, reach equilibrium, and then begins to swing back.
Dytter :: A brand of audible altimeter.
DZ :: Drop Zone; the landing area for the parachute delivery of cargo and personnel.
DZSO :: Drop Zone Safety Officer, who is the military equivalent of the Safety and Training Adviser (S&TA), a certified examiner and jumpmaster.
ears :: The stabilizing panels attached to the sides of the deployed ram-air canopy.
eddy :: A current running counter or contrary to the main current of air, especially when such variance has a rotary or whirling motion (such as a small whirlpool).
elliptical :: A wing or airfoil shape characterized by a tapering leading and trailing edge so that the middle of the canopy is wider, front to back, than the ends. This class of canopies with a tapered or approximately ovoid planform is a configuration that's typical of many high performance canopies. The "semi-elliptical" is a composite variant.
emergency parachute :: A secondary, backup, auxiliary or reserve parachute intended for emergency use, as by an aircraft crewmember; the packing of such is rigger certified.
end cell :: The farthest or outermost cells on a square canopy; the last chordwise section of a ram-air parachute canopy on either end.
end cell closure :: Deflated end cell on a ram-air canopy, which routine opening problem is usually correctable.
envelop :: The fabric structure enclosing the gasbag of an aerostat, being the surrounding or enclosing part; the integument or outer membrane comprising the gasbag itself.
equator :: A dividing line separating a dome-shaped parachute canopy into two accordant or congruous parts.
equipment check :: A pre-jump inspection of the parachute with its elements and attachments, such as a "pin check" on both the main and reserve containers; by self-examination or by "buddy check". Students are always checked on the ground by instructors or jumpmasters before boarding the aircraft.
exhibition jump :: A display or demonstration jump performed for spectators at a non-standard drop zone (DZ) for which the skydivers are compensated or rewarded, or their organization benefits.
exit point :: That point on the ground over which the parachutist jumps from the aircraft (spot), so as to land on the drop zone (DZ).
exit weight :: The total or combined weight of the fully suited jumper, together with all of the gear and equipment carried on that jump.
extraordinary skydive :: Any jump requiring special procedures or equipment, such as a night jump, water landing, pre-planned cut-away jump, exit or deployment above 15,000 ft MSL, an exhibition jump with props, or the like.
FAA :: Federal Aviation Administration; the government agency within the U.S. Department of Transportation that regulates civil aviation and air traffic, the certification of civil aircraft and their accessories, the licensing of aircraft pilots and mechanics, the certification of parachutes and riggers, including the regulation of skydiving. The FAA (formerly "Federal Aviation Agency") also administers the Federal Aid to Airports program.
FAI :: Federation Aeronautique Internationale; the international organization governing all air sports, including skydiving, and certifying all aeronautic and aerospace records; functioning through non-profit clubs in each country.
fairing :: A structure on the exterior of an aircraft (or watercraft) that's designed to reduce drag and to streamline its movement; any covering shaped to smooth airflow (or waterflow).
falling object :: See object.
fall rate :: The speed at which a skydiver falls, depending upon body posture and prevailing wind. The ability to match fall rates is essential to successful formation skydiving; which is accomplished with body position, jumpsuits, and weights. The 'fall rate' is not an absolute calculation (terminal velocity), but is measured relative to the descent of other skydivers, who are positioning themselves in proximity to each other.
FAR / FARs :: Federal Aviation Regulations, being part of the Code of Federal Regulations (CFR) and including Technical Standard Order (TSO); the laws governing aviation, including skydiving, as promulgated by the Federal Aviation Administration (FAA).
Farmer McNasty / Farmer MacNasty :: Disparaging referent for any unsympathetic or uncooperative neighbor of a drop zone (DZ), who either objects to the activity as a public disturbance, or seeks compensation for every inadvertent trespass; any DZ neighbor with whom relations are strained and communication is hostile ... an unenlightened boor or disenchanted philistine, being the proverbial "bad neighbor".
Federal Aviation Administration :: See FAA.
Federation Aeronautique Internationale :: See FAI.
Federal Aviation Regulations :: See FAR.
final approach :: The last portion of flight preparatory to landing, as of an aircraft or parachutist; also called "final leg".
finger trap :: A method of installing a loop in a brake line without producing rough spots on the lines, the finger trap is accomplished by sliding one line into the other. The loop serves as a method of setting brakes in the desired position for the parachute's deployment.
flare :: The conversion of descent speed into momentary lift, as when docking into formation or landing on the ground. The act of pulling down the brakes of the canopy in order to slow its glide, resulting in an increased angle of attack and reduced descent rate. When properly performed prior to landing, this stall results in an exceptionally soft landing. Also, refers to a membrane (diaper / slider) used to distribute the load of a parachute at the line attachment points of some canopies. Also, an incendiary device that may be activated during descent (either freefall or under canopy) as an extraordinary feature of a nighttime exhibition jump.
flat delta :: The triangular body posture, assumed in a horizontal plane, preliminary to tracking.
flat flying :: The primary freefall position of belly to earth; also known as "belly flying".
flexible harness :: The arrangement of adjustable webbing straps that're used to secure a parachute container (and its contents) to a person's body; in para-sailing, this personal harness links to the tow-bar ... as distinguished from the ridged para-sail gondola configuration that holds one or more persons in a seat connected directly to the para-sail canopy.
flight :: to maneuver a flying object (eg: airfoil, aircraft, parachute, etc) through the air, as by ascending, traversing, or descending; a trip through airspace.
flight bag :: A versatile carry-all or utility bag ("B4"), made with snap and zip closure, reinforced bottom, and wrap-around strap-handles; used for flight gear or paragear.
flight operator-in-command :: The person responsible for the conduct and safety of an airfoil or para-sail operation (aka: "para-sail captain"), and who is licensed to operate a winch boat or other mooring vehicle by the U.S. Coast Guard, the Federal Aviation Administration (FAA), or other similar regulatory agency.
flight tech / flight technician :: A trained adult crewmember, who's present aboard towing vehicles and alert to para-sail and glider operations, who's responsible for aerotowing prelaunch preparations, for monitoring of the towline and winch (ready for emergency intervention), and for post-launch recovery and maintenance of equipment; the flight tech is subordinate to a licensed 'flight operator-in-command'.
flight zone :: Any predetermined area, otherwise unrestricted, in which flight operations (including skydiving and parachuting) may be conducted.
floater :: Skydivers who leave the airplane before the base on large formation jumps must use a slow fall rate ("float") to allow the base to merge with them. Floating also refers to an exit position outside the airplane, which is so situated for early departure.
Flying Banana :: Nickname of the Boeing CH-21 Shawnee cargo / transport helicopter.
Flying Boxcar / Boxcar :: Fairchild Republic C-119 aircraft, with twin tailbooms and clamshell fuselage, which includes a rear loading ramp and side access doors.
Flying Oscar :: Nickname of the Boeing CH-47 Chinook cargo / transport helicopter after the Oscar Meyer wiener. [nb: 'Sea Knight' (CH-46) is the USN/USMC amphibious version (nicknamed "frog") of the Chinook]
F-111 :: (eff-whon-eleven) A fabric that's slightly permeable to air, and is commonly used on mid-range parachute canopies, but wears faster than zero-p ("zero-permeability") fabric. [nb: pronunciation is comparable to T-111 plywood that simulates joinery]
foreign parachutist :: Any parachutist who is neither an American citizen nor a resident alien, and who is participating in parachute operations within the United States by use of parachute equipment that was not manufactured in the United States. Also, an American parachutist granted reciprocity by a foreign nation to participate in parachute operations within that country, especially military personnel.
formation :: A freefall skydiving formation of more than one parachutist, often geometric. May also refer to a flight of more than one jump airplane.
formation skydiving :: The term formerly known as "Relative Work" (RW); abbreviated "FS". Aerial maneuvers by two or more freefalling skydivers with each other, usually to form geometric formations. Also, a competition involving the building of freefall skydivers into a formation, as regulated by the Federation Aeronautique Internationale (FAI).
frap :: To land at unsurvivable speed; also called "auger", "bounce", "pancake", "hammered", and "go in".
freefall :: Commonly called 'skydiving', it is self-deployed, self-regulated, and extremely versatile parachuting by use of various types of parachutes, launching from various aircraft or BASE locations at different altitudes. Primarily executed between aircraft exit and manual canopy activation, freefall involves body position to accomplish aerobatics and formations during descent. Specialized forms include RW / FS, freestyle, accuracy, HALO, and MFF. The definition of freefall has been extended to encompass CRW / CFS, HAHO, and LALO.
free-fly / free fly :: To exit unlinked with other jumpers.
free-flying / freeflying :: An unrestricted form of freefall style competition characterized by varied presentations to the relative wind.
freestyle :: A type of freefall maneuvering characterized by individual acrobatic flying, reminiscent of gymnastics; also known as "style" and "aerobatics". A choreographed solo performance of multi-orientation static and dynamic maneuvers exhibited as a competitive event, as regulated by the Federation Aeronautique Internationale (FAI).
frog :: A compact, face-to-earth body position in which the arms and legs are tucked against the torso, the neck retracts the head against the torso, and the minimal amount of steering is done with the hands beside the head; also called "bomber", "tuck", or "cannonball". This high-speed posture can quickly become unstable and turn into a tumble.
front :: An interface or zone of transition between two dissimilar air masses, differing in temperature and pressure.
front riser loops :: See dive blocks, riser loops.
FS :: Formation Skydiving; formerly known as "Relative Work" (RW) until the nomenclature was changed by the International Parachuting Commission. In FS, skydivers attempt to go through a predetermined sequence of freefall postures and formations, often forming geometric patterns.
full flight :: The stabilized state of hands-off canopy flight under a fully open and fully functioning parachute.
funnel :: When one or more skydivers find themselves in an unstable body position, they can generate a skydiver's burble, which can result in a loss of stability, and usually causes the formation to break up.
FXC :: A company manufacturing "fail-safe" Automatic Activation / Opening Devices (AAD/AOD), such as the ASTRA.
G :: The abbreviation for Gravity, being a sea level constant of gravitational force, as represented by increments of earth-surface atmospheric pressure, as experienced during accelerative torque or supersonic flight.
gang-bang :: Slang for a mass formation parachute jump or full unit Airborne assault; derived from the impressive appearance of a sky crowded by a mass of canopies ... it has the visual effect of canopies massively blossoming, like silent explosions, blotting-out the sky. It could also be called a "silken overcast".
gasbag / gas bag :: slang for the lifting envelope of a balloon, dirigible, or blimp.
glide :: The combined horizontal and vertical movement of an unpowered airfoil or of a descending parachute canopy.
glide angle :: The trajectory of a wing expressed as a ratio of the distance forward as compared to the altitude lost (eg: a 3:1 glide angle means the wing will travel three feet forward for every downward foot); also called "glide ratio".
glide path :: The proper alignment of heading or bearing for a descending approach to a landing. [cf: volplane]
glider :: A person or thing that glides. Also, a heavier-than-air aircraft, generally motorless with a high lift-to-drag aspect ratio (60:1), that's launched into soaring flight by catapult or towing; also called 'sailplane'. Originally built of lightweight wood, metal, and canvas, but are lately constructed of composite materials, such as polycarbonate resin (eg: Lexan), methyl methacrylate (eg: Plexiglas), aramid fiber (eg: Kevlar), woven fiberglass epoxy resin (eg: G10), thermoplastic polyamide (eg: Zytel), and the like. The Federation Aeronautique Internationale (FAI) classifies gliders by wing span and flaps; not by their (single or double) occupancy, (single or dual) controls, (skids or retractable wheels) landing gear, supplemental (ie: piston, rotary, jet or electric) engines, or the like. The stall speed for gliders (40mph) is less than that for motorized airplanes, and the maximum flight speed for gliders (170mph) is also less than that for motorized airplanes, but gliders can typically penetrate windy or turbulent conditions and can outrun the approach of bad weather. The military use of gliders during the interwar period was for aerodynamic research, and during World War II was for the disposable transport of men and materiel to a contested airhead. The use of rotary-winged gliders ('gyroglider') has been investigated as a method of airdropping people or equipment from transport aircraft so as to reduce their speed of descent and extend their glide path. [nb: the first practical, controllable glider was designed and built in 1849 by George Cayley, a British scientist who pioneered aeronautical engineering, which aircraft served to test aerodynamic theories and engage in sporting activities]
glide ratio :: The comparative distance a canopy flies forward while descending; sometimes called "glide angle". A canopy with a 3:1 glide ratio flies three feet forward for every foot of vertical descent.
glide slope :: The proper angle of descent from one altitude to another in the appropriate direction, as when making a landing.
gliding parachute :: A parachute canopy that's been modified with ports or vents to enable it to ascend and soar, as when being towed.
go-around :: An in-flight operation in which the jump aircraft circles the drop zone (DZ) at the exit altitude in a racetrack pattern; this orbit is employed when spotting the initial point, or for staged releases.
gondola / gondola support system :: In para-sailing, a rigid seating structure that supports one or more occupants in a partially seated or semi-reclined position that combines gravity restraint with harness webbing to secure the occupant(s) into that structure, which is directly attached to the para-sail canopy; this arrangement allows the occupant(s) to evacuate themselves in case of an emergency. Also, the passenger compartment that's suspended beneath a balloon or airship; also called "basket" or "car".
gore :: That portion of the dome-shaped canopy contained between two adjacent suspension lines, being the pie-shaped area between these lines that extends from the canopy's apex to its skirt.
governance manual :: The constitution and bylaws of the U.S. Parachute Association, including election of the directors and appointment of the officers, who have control of USPA property and funds, and are charged with conducting the affairs and advancing the goals of the USPA.
GPS :: Global Positioning System; a GPS receiver can identify the user's position from satellite signals, enabling a monitor to spot the proper exit for skydivers in a jump plane.
grabbing line :: See slip.
grab loops :: See dive blocks, riser loops.
Grand Caravan :: (forthcoming) 16-18 skydivers on a jump run
grippers :: Fabric handholds (eg: webbing strip, sausage roll, reinforced pad) built onto Formation Skydiving (FS/RW) jumpsuits to make it easier to take grips when docking or linking.
grips :: Slang for using the hands to hold onto another skydiver in freefall or during an aircraft exit. In formation skydiving (FS), the formations are scored as complete when every skydiver has taken the correct grips.
grommet :: A ring-shaped metal eyelet that's used as reinforcement around a hole in fabric, or as protection against abrasion for line running through it; on parachute rigs, grommets are used on pack flaps to fit over locking cones or loops.
ground effect :: The tendency of aircraft and other airfoils to glide farther when flying close to the ground.
ground hog :: Slang for anyone who works in a job that has nothing to do with aviation, airlift, airdrop, airmobility, or aircraft; used in the same discriminating way as "leg" for anyone who's not airborne qualified.
groundspeed :: The forward speed of an aircraft, airfoil, or skydiver moving over the ground, as opposed to its airspeed.
gyroglider :: An unpowered rotary-winged glider that utilizes an horizontal propeller to provide lift so as to reduce its speed of descent and to extend its glide path.
gyroplane :: An aircraft with an unpowered propeller rotating horizontally to provide lift while a powered propeller provides forward propulsion; also known as 'autogiro', a former trademark.
HAHO :: High-Altitude High-Opening parachuting technique.
HALO :: High-Altitude Low-Opening parachuting technique; first performed in 1941 from 30,800 to 1500 feet as a controlled demonstration to prove aviators could survive extreme delayed-opening ejections from disabled aircraft.
hand deploy / hand-deployed :: To activate the main canopy by manually deploying the small pilot chute during freefall, as opposed to pulling a rip-cord; also known as "pull-out" and "throw-out". A bridle tethers the pilot chute to the main canopy.
hand fairings :: Insulated mitts that slip over a glider's base tube, permitting the pilot to insert their hands for warmth.
hang check :: The final prelaunch inspection, while the pilot is hanging in harness and attached to the glider, so as to check the suspension system and to ensure that the pilot has hooked into the safety hang straps.
hang glider :: A semi-rigid kite-like airfoil consisting of a V-shaped flexible wing with the pilot suspended underneath, as launched from a BASE or tow, and controlled in its flight by the shifting of the pilot's body weight and posture. The Federation Aeronautique Internationale (FAI) designates several categories of semi-rigid Rogallo airfoils, some approved for foot-powered launching in nil wind and others with aerodynamic control surfaces (eg: spoiler, flap, elevator, aileron) and fairings. A rigid primary structure forms the shape of the flexible wing used in man-portable hang gliders, and this defining characteristic distinguishes them from the 'paraglider' or 'parawing' (FAI sub-class O-3), another type of foot-launched airfoil. Lightweight rigid wing hang gliders have been introduced to improve the glide ratio (15-19:1) of these airfoils over the glide ratio (10:1) of the original flexible Rogallo wing. An engine-powered hang glider with flexible wings over a rigid frame and a wheeled undercarriage (called a 'paraplane') is technically an 'ultralight' aircraft, despite all of its other similarities to a hang glider.
hang-glider :: The singular pilot of a motorless ultralight glider who is typically suspended beneath the flexible wing by its frame.
hang tough / hang tuff :: A catch-phrase of encouragement and solidarity for paratroopers who must endure bad weather, missed jump spots, and malfunctions to enjoy the privilege of parachuting ... such as having the guts to ride-out a Mae West under a full combat load onto an unsecured DZ at O-dark-30.
harness :: The adjustable webbing straps for securing a parachute container or pack (and its contents) to the jumper's body; the flexible harness used in para-sailing is also attached to the towline tether by a tow-bar. This type of personal body harness is distinguished from the ridged para-sail gondola, which holds one or more persons in a seat that's directly connected to the para-sail canopy.
harness-container / harness and container system :: The arrangement of webbing and fabric that holds the main and reserve canopies, together with their attachments and accessories, and secures them to the skydiver; useful in absorbing shock, distributing stress, and bearing load or weight. Different configurations exist to meet different needs and preferences. This harness and container system is generally unitized, and the entire element is designated "pack" by the FAA.
harness hold :: An Accelerated Freefall (AFF) technique that replaces the initial static line (SL) qualifying jumps with Instructor Assisted Deployment (IAD) freefall skydives. After ground training, the student is accompanied by one or more instructor jumpmasters during both poised and launch exits from an aircraft. The instructor(s) grip the student's harness so as to establish stability and to control maneuvers, and then pull the student's rip-cord to deploy his parachute at the appropriate altitude. This empirical methodology significantly increases the self-confidence necessary for the student to achieve self-supervised independent freefall proficiency.
HARP :: Abbreviation for High Altitude Release Point; since the flight path and jump run on High Altitude High Opening (HAHO) skydives must be different, this is the spot best calculated for parachute deployment, as factored by current wind velocity, actual jump altitude, and other variables, that will optimally attain the drop zone (DZ) objective with the mission specific equipment and requisite GEAR load. The HARP is the point at which freefall becomes paraglide, relative to life support and other crucial considerations. Formerly an elapsed time or distance plot computed before take-off, along with supplemental oxygen and related details, but since the availability of a real-time Global Positioning System (GPS), mid-air decision making has become standard procedure.
head down :: An inverted vertical or nearly vertical free-flying orientation.
heading :: The direction an aircraft, parachute, or skydiver is facing. The ability to recognize and maintain heading is crucial to successfully jumping with other parachutists. Exits and deployments are commonly described as "on" or "off" heading.
heavy drop :: The parachute delivery of cargo, supplies and equipment, which is always separate from parachuting people. The military additionally delivers vehicles, weapons, munitions, and other essential supplies to an established 'airhead'.
hell hole :: A hatch in the deck of some aircraft (eg: CH-47 Chinook) that may be used for passage outside the fuselage, as during rappel insertion or rope ladder extraction, paratrooper deployment or aircrew escape.
Hercules :: Lockheed four-engine, high-wing, turbo-prop, medium-capacity cargo / transport aircraft (C-130 / DC-130) introduced to USAF inventory in 1954; nicknamed "Herky bird" or "whisper pig".
HGMA :: The abbreviation for Hang Glider Manufacturers' Association (as established by Francis and Gertrude Rogallo, Charles Richards, Paul Bikle, Barry Hill Palmer, Mike Burns, john W. Dickenson, et al).
high alpha / high-alpha :: Flight profile that emphasizes a high angle of attack (in relation to the horizon) but without the airfoil climbing in altitude, especially while maneuvering at slower speeds.
holding :: To fly a parachute directly into the ambient wind; instead of crabbing against or running with the wind.
Hollywood blast :: Any parachute jump made without field gear or combat equipment, as one required each month for paratroopers to maintain their jump status, and to earn credit for supplemental jump pay; also called "Hollywood jump" from the show-off nature of such non-tactical formations.
Hooker harness :: A single-point aircraft passenger restraint system that integrates with a parachute harness; as designed by Jack Hooker.
hook knife :: A small emergency knife, carried in the jumpsuit or on the parachute harness, that is designed to cut through fouled lines or bound webbing. Resembling a seatbelt cutter, the knife forms a blunt hook around an inside cutting edge (such as a concealed razor blade), which only slices cord or fabric on a pull stroke. A variety of multi-blade or multi-tool knives intended for emergency and rescue use have incorporated a U-shaped hook blade; including the original WWII-era orange-handled MC-1 paratrooper's switchblade knife. Some short bladed hunting or survival knives with an integral "gut-hook" are also carried by parachutists for emergency use.
hook turn :: A fast sharp turn, often 90 degrees or more, executed close to the ground, resulting in a dive landing; a risky maneuver employed to counteract wind or drift shifts, to avoid hazards, or to acquire speed just prior to landing.
hookup / hook-up :: To grasp onto or link-up with other skydivers in freefall, as in building a formation; to link, dock, pin, grip, join, or connect. Also refers to securely fastening the static line onto an anchor in the jump plane; as a safety precaution, this coupling is not made until the aircraft is on final approach to the spot during its jump run.
hop 'n' pop :: Slang reference to a static line deployment wherein the parachutist departs the aircraft ('hop') and the jumper's main canopy is then automatically released ('pop') about four seconds later by the tethered static line.
horseshoe :: A partial parachute malfunction wherein part of the deployed parachute is entangled with the jumper or with their equipment, as when the canopy isn't fully released from the D-bag.
hot fuel / hot-fueling :: The refueling of an aircraft without shutting down its engine(s); due to the risk of fire, no passengers should be on-board during this procedure.
Huey :: Nickname for the Bell utility helicopter (UH-#) series, which is formally known as Iroquois.
hump :: Slang for de-arch (qv).
Husky / Huskie :: Single-engine Kaman helicopter (HH-43 USAF) with twin offset main rotors and stabilized split tailboom; nicknamed "Mixmaster", this heavy-lift helicopter was designed for crash-rescue operations.
IAD :: Instructor Assisted Deployment, including "harness hold" (AFF) and "piggyback" (tandem) modalities. In an IAD deployment, the instructor guides the passive student during initial exit and freefall stabilization, and then activates parachute deployment by controlling its release (by rip-cord or throw-out) at the appropriate altitude.
ICC :: Instructor Certification Course, which must be successfully completed in order for a jumpmaster to be qualified to teach skydiving techniques to a student.
I/E :: See instructor/examiner.
impetus :: The momentum of a moving body, especially with reference to the cause (stimulus or driving force) of its motion.
initial point :: See spot.
in date :: As noted on the data card, a reserve parachute that has been packed (inspected and repacked) within the previous 120 days; it is illegal to jump with a reserve chute that is "out of date".
indraft :: An inward flow or current of air, as when drawn in.
instructional rating manual :: The collection of documents and references required to conduct any course for qualifying an USPA coach or instructor.
instructor :: A parachutist who has held a USPA jumpmaster rating for at least one year and passed an Instructor Certification Course in at least one of the approved deployment techniques. An "instructor" rating is mandatory for managing student programs and licensure sign-offs. An instructor is eligible to coach contestants, to supervise competitions, and may be appointed as a Safety and Training Adviser (S&TA). An Instructor/Examiner is certified to teach instructors.
Instructor Assisted Deployment :: See IAD.
instructor/examiner :: The USPA certified Instructor/Examiner (I/E) is qualified in all deployment methods, passed all proficiency exams, licenses instructors, and serves as a Safety and Training Adviser (S&TA).
International Parachuting Commission :: See IPC.
inversion :: A reversal in the normal temperature lapse rate, wherein the temperature rises with increased elevation instead of falling; also called "atmospheric inversion" and "temperature inversion", being a weather condition in which warm air is trapped aloft, inhibiting thermal development.
IPC :: The International Parachuting Commission is a committee of the Federation Aeronautique Internationale (FAI), and oversees sport parachuting worldwide.
IRM :: See instructional rating manual.
Iroquois :: Bell UH-1 utility helicopter series; nicknamed "Huey", from its 'UH-#' designation; chosen in 1955, with delivery beginning in 1959, the open-sided Iroquois proved to be faster, more maneuverable, and more versatile than the CH-34 Kingbee and CH-21 Shawnee as an assault platform. Static line parachuting, as well as rappelling, was executed from the Huey's landing skids.
jet stream :: Strong winds, generally westerly, concentrated in a relatively narrow and shallow stream in the upper troposphere of the earth. Also, the backwash (wash) or exhaust of a jet airplane engine. Also, the flow of currents (slipstream) against or around a person or airfoil moving faster than the ambient wind.
JM :: Abbreviation for jumpmaster (qv).
JOES :: Jumpers Over Eighty Society, acronym for the worldwide association of superannuated skydivers and parachutists (2002). [v: POPS]
Jolly Green Giant :: Nickname for the Sikorsky single-rotor, heavy-lift cargo helicopter (USAF CH-53 / HH-53 / HH-3) used for transport or rescue operations. [nb: 'Sea Stallion' (HH-53 / MH-53) is the USN/USMC amphibious version (nicknamed "echo") of the Jolly Green Giant; the 'Sea Stallion' was succeeded by the Sikorsky Super Sea Stallion (CH-53E)]
JONS :: Jumpers Over Ninety Society, acronym for the worldwide association of superannuated skydivers and parachutists (2014). [v: POPS]
JOS :: Jumpers Over Seventy, acronym for the worldwide association of superannuated skydivers and parachutists (1999). [v: POPS]
JPADS :: Joint Precision AirDrop System, being a computer-controlled parachute delivery method used to supply or resupply troops in the field with rations, fuel, ammunition, and other vital necessities. After exiting a cargo plane flying as high as 25,000 feet above the ground (AGL), the wing-shaped steerable ram-air parachute self-maneuvers using Global Positioning System (GPS) coordinates to a drop zone (DZ) as small as 100 meters, making aerial delivery of a 2000# PAYLOAD securely. The JPADS is not only capable of traveling significant distances from its aerial release point, but can separate different parachutes released at the same time so as to deliver different payloads to different ground locations.
judge :: The official who evaluates the performance of competitors during sanctioned meets; the USPA issues judge ratings at both the conference and national levels, while the FAI issues a rating for internationally recognized judges.
jump altitude :: The actual altitude of an aircraft above the ground (AGL) at the time a skydiver exits.
jump boots :: Sturdy but comfortable boots that protect the feet and ankles of parachutists, often with thick soles, reinforcing quarters, and tendon protection. Lighter-weight jump boots, such as high-tech hikers, are often used by sport jumpers and competitors.
jump lift :: The assignment of parachutists to a program or schedule; the manifest for any single flight.
jumpmaster :: A military parachutist certified to instruct, supervise, and conduct airborne personnel and operations; the airborne-qualified individual assigned to control the parachutists or paratroopers from the time they enter the aircraft until they exit. The jumpmaster coordinates boarding and exit order, jump flight procedures, target spotting, and emergency operations with the pilot of the aircraft. All licensed civilian skydivers "jumpmaster" their own deployments; but a civilian jumpmaster (minimum USPA C license rating) is certified to supervise parachutists and conduct parachute events, such as formations. Civilian jumpmasters must be "instructor" qualified to manage student jump programs and sign-off on licenses. All military freefall (MFF) personnel are also civilian certified jumpmasters. Sometimes abbreviated 'JM'; and may be designated "monitor" outside the USA.
jump plane :: A utility or cargo aircraft, often of the Short Take-Off and Landing (STOL) type, including Twin Beech, King Air, Caravan, Cessna 182, Cessna 205, Skymaster, Porter, Bronco, Otter, Beaver, Twin Otter, SkyTruck, CASA 212, Dakota, Caribou, Provider, Flying Boxcar, Hercules, Kingbee, Huey, Shawnee, Chinook, Husky, Jolly Green Giant, and the like; also called "jump ship" or A/C.
jump run :: The predetermined flight path taken by the jump plane to accurately place the skydivers in position over the landing area or drop zone (DZ).
jump ship :: See A/C.
jump speed :: The airspeed at which parachutists, paratroopers, and other aircrew can exit with comparative safety from an aircraft.
jump spot :: See spot.
jumpsuit :: A coverall-type garment specifically designed for skydiving applications, by inclusions and modifications, such as FS, freestyle, or accuracy.
katabatic :: A wind or air current that is moving downward; compare "anabatic".
keel :: The main structural tube that runs along the wing or sail at its center chord on a glider.
keep on trackin' :: A freefall-specific corruption of the once-popular "Keep on truckin'!" expression that was made famous during the 1970s in the "Mister Natural" cartoon series by Robert Crumb; versions of this character, together with the altered tag line, adorned many bulletins and advertisements of the era.
key :: A signal to proceed to the next step in a skydiving sequence.
kinetic energy :: The energy of a body with respect to its motion. [cf: potential energy]
King Air 90 :: A turbine-powered airplane manufactured by Beechcraft that's suitable for take-offs from and airdrops onto medium-sized drop zones (DZ); this low-wing airplane is fast and economical, but has a small exit door for serving 12-15 skydivers on a jump run.
King Air 200 :: (forthcoming) fast and quiet, but with small door for 22 skydivers on a jump run
Kingbee :: Sikorsky CH-34 cargo and troop-transport helicopter, which had a large loading aperture on its starboard side, making it suitable for parachuting and rescue operations; also known as "dog" and "ugly".
kingpost :: The vertical strut running between the apex and base of a glider that supports negative rigging and luff line systems.
kite :: An airfoil that's tethered to something else (fixed or mobile), requiring the passage of wind to generate lift and drag; a light framework covered with some thin material that's to be flown in the wind at the end of a long retaining line.
kite line :: The tether or retainer (fixed or mobile) that must maintain tension so as to generate lift and drag in the kite being flown.
knee hangers :: The supports used to hold-up the pilot's legs on some hang glider harnesses.
Kodiak :: (forthcoming) economical fuel but high maintenance, with large door for 12 skydivers on a jump run
kytoon :: A captive balloon kite that's been shaped by combined features to obtain aerodynamic deflections, and has been developed for lighter-than-air, neutrally buoyant, or heavier-than-air commercial applications, including airborne wind energy systems and meteorological monitoring at a fixed height; term derived as a blend of kite and balloon.
LALO :: Low-Altitude Low-Opening parachuting technique; primarily employed by military skydivers.
landing pattern :: The deliberate flight path, usually rectangular, that a jumper uses in the final phase of descent under canopy.
LAPES :: Low Altitude Parachute Extract/Extraction System, wherein a drogue is used to extract para-dropped cargo from the open fuselage of an airplane in flight.
lapse rate :: The rate of decreasing atmospheric temperature with the increase of vertical elevation above a given location; a measure of air cooling at higher altitudes.
LAR :: The Launch Acceptance Region estimated by pre-flight or in-flight mission planning for an airdrop.
LDR :: Abbreviation for let-down rope, an auxiliary tether connecting a gear bag to the parachute harness.
leading edge :: The edge of an airfoil or propeller blade that's facing in the direction of motion or movement. Also, the forward edge of an air mass.
leg :: Slang for any non-parachutist; someone who is not Airborne qualified; also called "straight leg" and "wuffo". Also used to designate a portion or segment of an action or maneuver, as the first phase or the final aspect.
leg strap / leg-strap :: See thread through, B-12s.
let-down rope :: An auxiliary line carried whenever a tree landing may capture the parachute canopy, being a 5mm or 7mm cord of about 75-150 foot length that's typically carried in a leg pocket for deployment whenever necessary, by securing one end to the parachute harness and then body rappelling down to the ground ... this escape line is left in place to assist in the later retrieval of the entangled para gear. If a paratrooper utilizes an equipment bag (ie: dingleberry) that's tethered to the parachute harness by a "lowering line", then an auxiliary let-down rope may not be necessary. Instructors often teach students to employ the reserve chute as a method of descending to the ground if suspended in a tree, but that solution relies upon the availability of a secondary canopy, the space to deploy such a voluminous alternative, and the unavoidable expense of repair or replacement and certified repacking. This escape line is a necessary adjunct for smokejumpers, and a useful tactical supplement for paratroopers.
level wind :: A device attached to a winch that enables the towline to uniformly wrap and unwrap from the winch spool.
license :: A certificate of proficiency recognizing that a skydiver has met the specified level of knowledge, skill, and experience in one of the four classes (ie: A - D) of USPA licensure which are recognized internationally through the Federation Aeronautique Internationale (FAI).
lift :: That component of force, opposite to the pull of gravity, exerted by air upon an airfoil in a direction perpendicular to its forward motion; the effect of lift elevation can only be maintained by sufficient forward motion and an adequate updraft of rising air.
lift-to-drag ratio / lift-to-drag aspect ratio :: The relative degree of ascent and retardation attainable by the configuration of a particular airfoil; this inherent aspect ratio, factored by winds aloft, determines a wing's glide ratio.
line dock :: The docking of two canopies with the docker's canopy above the head of the person receiving the dock.
line of flight :: An imaginary line corresponding to the jump plane's path over the ground, which is useful when plotting larger formation skydives because the skydivers will be distributed along this line during the jump run.
lineover :: A partial malfunction of a deployed parachute resulting in one or more suspension lines going over the top of the canopy; commonly known as a "Mae West" on parabolic rigs. This configuration may generally resemble a "partial inversion" of a round canopy, but they are formed differently.
line twist :: A condition of parachute opening where the canopy has attained full or nearly full inflation but one or more complete twists have developed in the suspension lines and/or risers. An eventuality that can be dangerous when associated with a spin.
loadmaster :: The aircraft crewmember who is responsible for the proper stowage and movement of transported men, equipment, or other cargo, for the optimal balance and protection of the payload.
loft :: An open or unpartitioned building with a high clearance, as if for an upper story, used for the care and repair of parachutes, their inspection and packing. This facility also serves as a venue for safety lectures, instruction, "dirt diving", gear stowage, and other social activities, including celebratory "prop blasts". If situated near an airstrip or drop zone (DZ), the loft may include a "ready room" where standby or on-call personnel may await their turn for a jump lift, or their duty assignment.
logbook / log book :: An authenticated record (countersigned by a responsible witness) of someone's flying or parachuting experience, citing date, place, equipment, weather, and performance of each event, which log is submitted whenever a candidate applies for further training or a higher rating. Also, the ownership, maintenance, and related activities for a governmentally regulated airfoil (eg: parachute, para-sail, glider, etc); the absence, neglect, or alteration of which is illegal. Also, an account detailing the travels, maintenance, and related activities of a ship, aircraft, or other official vehicle.
LORAN :: A "LOng-RANge radio-navigation" position fixing system using the time difference of reception of pulse type transmissions from two or more fixed ground stations. "LORAN" is being made obsolete by the global positioning system (GPS), and US military and maritime elements ceased its use during the early 1990s.
lowering line :: The section of rope or webbing strap (about 15-30ft length) that tethers an equipment bag (ie: dingleberry) to the parachute harness, so that it can be lowered to hang under the paratrooper after the main canopy has properly deployed, where it is safely out of the way when it's time to execute a parachute landing fall (PLF); not to be confused with an auxiliary let-down rope (LDR).
luff :: The vibratory effect of a canopy or airfoil flying into the wind at a too-steep angle of attack, in which the leading edge may tremble and the entire surface may ripple. An effect similar to waffle, but from a different cause.
luff lines :: The lines running from the kingpost to the trailing edge of a glider's wing, which serve as Aids to dive recovery.
Mae West :: A partial parachute malfunction where the suspension lines divide the main canopy into two sections, like a gigantic brassiere; derived from name of famous full-breasted actress. Formally known as a "lineover", but also resembles a "partial inversion".
main :: The primary parachute, or the largest canopy; normally deployed by a pilot chute, and intended to be used with a reserve available for emergency deployment.
maintenance :: The normal inspection, overhaul, repair, preservation, and replacement of standardized integral parts.
major alteration :: An alteration not listed in the manufacturer's specifications that might appreciably affect weight, structural strength, performance, flight characteristics, or other qualities affecting airworthiness, or that cannot be done by elementary operations.
major repair :: A repair that if improperly accomplished may affect weight, structural strength, performance, flight characteristics, or other qualities which determine airworthiness.
mal :: Short form of 'malfunction'.
malfunction :: The complete or partial failure of a parachute canopy to attain or sustain proper opening, descent, or flight characteristics.
manifest :: The list of parachutists scheduled for any particular flight; used for purposes of accountability and load management.
manned para-sail :: A moored para-sail with a person (ie: para-sailor) attached.
master :: The expert rating for military parachutists requiring jumpmaster training and a minimum of sixty-five static line jumps, which qualification is oriented to vertical tactical operations.
master blaster :: Slang for someone rated as a master parachutist or jumpmaster.
mechanical aerodynamic wedge :: See Cooper vane.
MFF :: Military Free Fall parachuting; the tactical form of skydiving employed by Armed Forces personnel.
microline :: Suspension line cordage that's narrower, but with equal or greater strength than traditional Dacron® 550 polyester para-cord; typically made of Spectra® material.
minimum sink speed :: The slowest speed at which a gliding airfoil can be made to descend through the air; the greatest retardation of drag consistent with flight.
minor alteration :: Any minor change or modification to any part of the parachute assembly from its original manufacturer's specifications.
minor repair :: Any mend or reinforcement made to any part of the parachute assembly so as to sustain its airworthiness.
mission planning :: The detail planning of an airdrop mission by pre-flight or in-flight use of a rugged (high-pressure tolerant) laptop computer, with a software interface accepting aircraft, environment, and load data, that'll factor known parameters so as to ascertain the precise aerial release point for delivery onto a specific ground location (DZ); this system's key modeling parameters include aircraft position, altitude, airspeed, heading, steering waypoints, ground speed, course, onboard load position (station), drop altitude, roll-out / exit time, wind magnitude / direction, decelerator opening time, trajectory to stabilization, and descent rate.
momentum :: A quantitative representation of the motion of a body, which is equal to the product of the mass of that body and its velocity. Also, the force or speed of movement, as of a physical body; the causative impetus of a course of action. [v: law of conservation of linear momentum, law of conservation of angular momentum]
mooring vehicle :: The vehicle or vessel to which a towed object (eg: para-sail, rotor kite, glider, etc) is tethered by a towline; a platform mounted with the apparatus for towing people or objects, together with rescue, recovery, weather, and communications equipment.
mother hen :: Slang for the leader of a chalk or stick, functioning as a team, squad, or section leader to get "all the little chicks in a row"; properly known as a stick commander or chalk commander.
motorless aircraft :: See unpowered aircraft.
MSL :: Mean Sea Level; used to designate altitude in feet above sea level, as opposed to above the ground (AGL). Pilots of aircraft always use MSL when referring to altitude.
mushroom :: Slang for a parabolic canopy or a round parachute. Also refers to a cat's-paw, pawn, or dupe who is used in covert operations without full knowledge, as being "kept in the dark and fed on horse shit".
Mylar® :: A brand of strong, thin, smooth polyester film that's used to stiffen the flexible wing on gliders and similar airfoils.
NAA :: National Aeronautic Association; the national aero club of the USA which represents the Federation Aeronautique Internationale (FAI). USPA is a division of the NAA.
nacelle :: The enclosed part of an airplane, dirigible, or the like, in which the engine, cargo, or passengers are housed. Also, the car of a balloon; as derived from a "small boat".
NAS :: National Aircraft Standard, which defines the minimum performance ratings, the safety standards, and the tests required for a parachute to be approved by Technical Standard Order (TSO) C-23b. NAS 804 was adopted in 1949, and was superseded in 1984 by NAS 8015A.
NASA :: The abbreviation for the National Aeronautics and Space Administration, a federal agency.
Nasser toggles :: Control loops on the front risers attached to one or more A or A-B lines to facilitate diving the canopy toward a canopy (CRW / CFS) formation. Designed by Nasser Basir.
National Aeronautic Association :: See NAA.
National Aircraft Standard :: See NAS.
NCPC :: National Collegiate Parachuting Committee; the organization that encourages and supports the collegiate sport of skydiving, and conducts annual championships.
Nicopress® :: A brand of metallic oval slug that's used to clamp cables.
night jump :: The FAA recognizes any parachuting between one hour after sunset and one hour before sunrise as a qualifying "night jump", regardless of moon phase or weather conditions; a requirement of both military and civilian parachute qualification.
nose angle :: The angle of an airfoil's leading edges to each other when viewed from above or below.
nose plate :: A metal plate positioned at the junction of the keel and leading edges of a glider.
NOTAM :: Notice to Airmen; an air traffic advisory or notice filed with an FAA Flight Service Station by an airspace user.
Nyloc® :: A nut with an elastic nylon insert that prevents accidental unthreading.
object :: Any item, other than a person, that falls to the ground or descends to the surface from an aircraft in flight or from an aerial platform aloft when a parachute is used or is intended to be used during all or part of the descent; also called a "falling object", and may include dislodged paragear or a paracargo payload. Any uncontrolled or unguided falling object is an airborne hazard, and may be harmful to skydivers, air crew, and ground personnel.
open body of water :: Any water hazard or other uncovered body of water in which a parachutist could land, and therefore might drown.
opening point :: The reference ground point over which the freefall skydiver opens their parachute.
opening shock :: The sudden force experienced by the jumper when the fully deployed parachute abruptly slows the rate of descent from terminal velocity. This rapid deceleration, also called "opening force", is caused by the resistance of load exertion during canopy inflation.
organizer :: Someone with enough leadership skills and skydiving expertise to plan formation skydives.
oscillation :: The swaying or swinging motion, resembling a pendulum, of the suspended load under a deployed canopy; may be caused by wind variations, improper steering, inadequate venting, excessive movement or manipulation. In canopy formations, such oscillations may result from poor docking or other internal turbulance.
Otter :: A fixed-wing light cargo aircraft (U-1) that's manufactured by DeHavilland, and capable of short take-off and landing (STOL) by wheels, skis, or floats.
outboard :: Oriented to the outside or outermost (distal) aspect of the parachutist, as when facing the rip-cord handle for actuation by pulling away from the body. An outboard orientation often limits access to only one hand, and increases the risk of accidental dislodgment through inadvertent contact or friction.
out landing :: Landing off of the target area; also, landing outside the drop zone ... humorously expressed as "outlandingish" or just "outlandish".
out of date :: As determined by the data card, a reserve parachute that has been packed longer than the previous 120 days; it is illegal to jump with a reserve chute that is "out of date".
overcast :: A sky almost completely covered by clouds; the firmament overspread with clouds. Also, to sew fabric with long, spaced stitches that pass successively over an edge to prevent raveling.
PAC 750 :: (forthcoming) economical fuel but high maintenance, with large door for 15 skydivers on a jump run
pack :: The FAA term for a parachute assembly without the harness; includes the container, canopy, suspension lines, pilot chute, risers, and connector links. This term is synonymous with 'container'; also known as "parachute pack". Also, the proper and precise folding and layout of a parachute canopy and suspension lines within its deployment container.
packing data card :: Also called data card (qv).
pack sack :: Slang for the bag or deployment bag, which is secured with the suspension lines in the container or harness/container.
pack tray :: The part of the container (or harness/container) where the folded canopy and aligned suspension lines are fitted for secure stowage and proper deployment. Name probably derives from its resemblance to primitive backpacking frames, which were camping supplies encased by a shelter-half that was secured with diamond-hitches ... in order to get at anything, everything had to be exposed, which is exactly how the harness/container functions during parachute deployment.
pancake :: To land at unsurvivable speed; also called "auger", "bounce", "frap", "hammered", and "go in".
panel :: A distinct triangular or trapezoidal section fitted vertically into a parabolic or round parachute canopy, which may be vented or reinforced, and is anchored by suspension lines. Also refers to a lateral subdivision of an airfoil with internal girder construction.
para :: Short for parachute, parachuting, or parachutist. [nb: meaning 'sustain'; not 'beside' or 'subsidiary']
paracargo :: Any payload delivered by parachute.
parachute :: An umbrella-like fabric deceleration device; being a parabolic, ram-air, or other airfoil system used primarily for the vertical delivery of men or equipment from an altitude onto a designated landing area or drop zone (DZ). Parachutes intended for human use are sized approximately 24 - 35 foot diameter canopies, and cargo chutes are sized approximately 48 - 60 foot diameter canopies, and may be deployed in multiples. Parachutes designed for improved steerability, often called "sport parachutes", are modified with ports or vents that can be actuated by the jumper to help control direction and descent. The word 'parachute' (parer + chute) derives from "sustain + fall" for a "deployable aerodynamic decelerator", and was coined by Louis Sebastien Lenormand in 1783. [nb: the USPA alleges that parachute derives from "shield + fall" meaning a protective or preventative device to arrest a fall, but the pre-aviation intent of the inventors was to enable a controlled descent]
parachute drop :: Formally defined as the descent of an object (non-human) to the surface from an aircraft in flight when a parachute is used during all or part of that descent, but is typically used as a synonym for "parachute jump".
parachute jump :: A parachute operation that involves the descent of one or more persons to the surface from an aircraft in flight when a parachute is used during all or part of that descent.
parachute landing fall :: The PLF is a technique used to minimize injury during rough landings; a PLF distributes the landing shock along feet, calf, thigh, hip, flank, and shoulders. During a PLF, the jumper's chin is tucked, and the risers are grasped in an arm-bar protecting the face and throat. The PLF is executed in one of six directions (left front, left side, left rear, right front, right side, right rear), depending on terrain, wind, and oscillation. A smokejumper's PLF differs in that it transforms into a tumble once the hip has struck the ground.
parachutist :: Anyone who uses a canopy or airfoil to descend an altitude, with (freefall) or without (static line) a delay in deployment of the device; according to international law, a parachutist is a 'noncombatant', as distinguished from a 'paratrooper'.
parachutist in command :: The person, usually the instructor, responsible for the safe control and operation of a tandem jump with a "passenger parachutist". The person in command is always behind and slightly above the passenger, but is not necessarily a jumpmaster.
para-cord :: Contraction of parachute cord, a thin, multi-strand, sheathed suspension LINE used to connect the harness risers to the canopy, but widely adopted for many other utilitarian applications; also called 550-cord, ranger cord, or p-cord.
parafoil :: An arrangement of sectioned cells in an airfoil shape that was patented by Domina Jalbert on 10 January 1963; it consists of an open leading edge and a closed trailing edge that's inflated by passage through the air in a ram-air configuration that was developed further by David Barish for the recovery of space capsules for NASA.
paragear :: The aggregate of clothing, equipment, and supplies used in parachuting, and usually carried in a flight bag.
paraglide /-ing :: A flight activity, also called 'parapente', involving the use of an airfoil or a ram-air inflated wing (resembling a "square" parachute) in surface lift-off gliding. Flights are typically initiated by foot-launching from a hill or from a ground-based tow. Because paragliding does not meet the definition of "the descent of a person or object to the surface from an aircraft in flight", it is not regulated by the FAA nor addressed by the USPA.
paraglider :: A steerable glider with inflatable wings that was first proposed during World War II for use as an emergency vehicle for travel between a space station and the earth, or for the recovery of rocket boosters; term coined in the early 1960s by the National Aeronautics and Space Administration (NASA), and is also called 'parawing' (FAI sub-class O-3). This inflated wing glider (10:1 glide ratio at 28mph) differs structurally from a flexible wing hang glider, which is frame mounted. A paraglider wing powered by a motor attached to the back of the pilot is known as a 'paramotor' or a "powered paraglider".
paramotor :: An inflated wing paraglider that's powered by a motor attached to the back of the pilot, and is also called a "powered paraglider".
paranoid :: A "bad news" parachutist who devoutly believes that luck or fate is more significant than skill or technique in skydiving; an accident waiting to happen!
parapente :: See paraglide.
paraplane :: An ultralight aircraft consisting of flexible wings over a rigid frame and an engine-powered wheeled undercarriage, despite all of its other similarities to a hang glider.
para-sail / parasail :: The recreational sport combining air foil soaring while being towed as a water skier; someone suspended by an ascending parachute on a towline that's deployed from a mooring vehicle that's underway.
para-sailor :: The water skier who is towed aloft by a winch boat while wearing a harness (flexible or ridged) that's attached to a deployed canopy by a towline.
parascend /-ing :: The ascent of one or more persons who're suspended from a parachute canopy that's tethered to a towing vehicle, and are deliberately released at a specific altitude above land or sea level, so as to execute a conventional (disconnected) parachute descent and traditional landing; a variation on sport jumping, this portmanteau term blends 'parachute' and 'ascend'.
para-scuba :: The combination sport of parachuting into water with skindiving equipment already emplaced; a water jump that transitions into a scuba dive.
para-ski :: The combination sport of parachuting onto a snow-covered mountain (typically so remote as to be otherwise inaccessible) with downhill (alpine) skiing equipment already emplaced; downhill skis or a snowboard can be used like a "skyboard" during freefall for "skysurfing" before deploying the chute and landing on the mountainside.
para-skier :: The snow skier who parachutes above a (remote) snow-covered hillside while wearing (downhill) skis or a snowboard so as to skysurf during freefall before landing.
paratrooper :: An armed soldier with skills so essential to the objective that he is delivered, with all of his necessary equipment, to the battlefield by air transport, where he must sustain the mission until joined by conventional ground forces. According to international law, a 'parachutist' is a noncombatant.
parawing :: See paraglider.
partial inversion :: The inflation malfunction of a round canopy where one side passes through two lines of the other side before partially inflating as separated lobes. The resulting configuration may resemble a "lineover" but is formed differently.
passenger parachutist :: The person, usually a student, who exits the jump aircraft while secured to the forward harness of a dual-rig tandem parachute system for descent to the ground.
pathfinder :: The advance element for an airborne or heliborne insertion of operational units. Pathfinder teams were dropped or air-landed at an objective to establish a Drop Zone (DZ); or air-delivered into enemy territory for purposes of determining the best approach and withdrawal lanes, Landing Zones (LZ) and airhead sites for heliborne forces.
pax :: The abbreviation for 'passenger', as when designating someone who's without crew responsibility on an aircraft; also known as BLOB, sandbag, or strap-hanger.
payload :: The cargo load of necessary supplies and equipment on an aircraft essential for the performance of a given mission, or the accomplishment of a specific sortie.
peas :: Pea-sized gravel, used in the landing area as a target reference, and because it is forgiving of hard landings.
penguin :: Nickname for non-flying aviation support staff and ground crew, by analogy with flightless bird; as used since before WWII, and also known as "wing wiper". This affectionate name was selected due to the derogatory associations with other choices, such as Ostrich, Dodo, Moa, Emu, Cassowary, Great Auk, Kakapo, and Kiwi.
permeability :: The amount or volume of air which is capable of passing through a porous fabric assembly without damage.
piggyback :: See tandem.
pilot :: A person qualified to operate an airplane, helicopter, balloon, glider, or other aircraft in flight.
pilot chute :: A small round parachute that acts as a drogue to initiate and/or accelerate the extraction of the main or reserve canopy from its bag or container for deployment. A bridle tethers the pilot chute to the main canopy.
pilot chute assist :: A method of rigging a static line to a parachute where the static line opens the container and positively extracts the pilot chute before the break cord (of known strength) or Velcro strip separates the static line from the parachute system. A bridle tethers the pilot chute (drogue) to the main canopy.
pin :: The first skydiver to dock or link onto the base; this pin is the essential second element in building a formation. Also refers to the closing or retaining pins of the container of the main and reserve chutes, both of which should be checked prior to jumping.
pin check :: Pre-jump inspection of the parachute, especially the closing or retaining pins.
pit :: The pea gravel landing area serving as a target on the drop zone (DZ). Also, in jump school ground training, the sand-filled pit where parachute landing falls (PLF) are practiced.
pitch :: The up or down nosing of an aerodynamic body about its transverse axis; a longetudinal oscillation or linear plunge, as when alternatively rocking forward and back (pitch-pole).
plane :: The placement or arrangement of a compact or compressed formation distributed in a single level of altitude or across a geometric surface; also called "planing". Also, short form of 'airplane', being any of numerous heavier-than-air aircraft that are variously propelled into aerodynamic flight, especially the jump plane; an A/C.
planform :: The outline of an object when viewed from directly overhead, especially the footprint of a wing surface.
PLF :: Parachute Landing Fall. A technique used to minimize injury during rough landings; a PLF distributes the landing shock along feet, calf, thigh, hip, flank, and shoulders. During a PLF, the jumper's chin is tucked, and the risers are grasped in an arm-bar protecting the face and throat. The PLF is executed in one of six directions (left front, left side, left rear, right front, right side, right rear), depending on terrain, wind, and oscillation. A smokejumper's PLF differs in that it transforms into a tumble once the hip has struck the ground.
pod :: Informal reference to a fully-enclosed soaring harness.
point of departure :: See spot.
poised exit :: An incremental departure from an aircraft wherein the jumper uses the external structure of that aircraft (ie: strut, flap, boom) to momentarily brace himself so as to assist in gaining a stable body position immediately upon leaving the aircraft. This is an excellent teaching method for novice skydivers, especially during initial SL or DRCP jumps.
POPS :: Parachutists Over Phorty Society, the acronym for the worldwide association of superannuated skydivers and parachutists (1966); further subdivided into Skydivers Over Sixty [SOS (1992)], Jumpers Over Seventy [JOS (1999)], Jumpers Over Eighty Society [JOES (2002)], and Jumpers Over Ninety Society [JONS (2014)].
porosity :: The ratio of open to closed areas in a fabric, which are graded as high, low, or zero; tightly woven and treated material has a lower porosity than loosely woven material.
Porter :: A light, tail-dragger airplane made by Pilatus with a single turbine engine of the short take-off and landing (STOL) type that transports 9-10 skydivers on a jump run.
position :: See body position, slot.
post dive :: Analysis of a skydive after all participants have landed; such an 'after action review' or "cold wash" is intended as constructive criticism for individual betterment and improved coordination.
posture :: See body position.
powered paraglider :: See paramotor.
practice deployment :: An in-air exercise used to accustom the novice jumper to the location and operation of a rip-cord or parachute deployment handle prior to autonomous opening. This exercise, formerly called "Dummy Rip-Cord Pull" (DRCP), is conducted under instructor supervision, as IAD or AFF, or while tethered to a static line (SL), and may consist of pulling or throwing a practice handle, or of simply touching the actual deployment handle in freefall or tandem drogue fall.
premature opening :: The unintentional opening of a parachute. If done inside an aircraft just before or during the exiting stage with hatches open to ambiant winds, this accident may prove catastrophic.
prop blast :: The turbulent backwash encountered by a parachutist upon exiting an aircraft in motion; a disturbance that can disorient or injure the jumper. Under optimal conditions, the pilot will feather the airplane's propeller thrust at the coordinated spot (or "exit point") on a jump run, but the mission or weather conditions may not permit this accommodation. Parachutists who exit an aircraft by its 'tailgate' (eg: C-119 Flying Boxcar, C-130 Hercules, CH-47 Chinook, HH-43 Husky) often experience much less "prop blast" than when exiting the same aircraft by its 'side door'. This phrase also refers to the unique initiation ceremony, often ridiculously ritualized and rowdy, that celebrates the qualification of new skydivers or the assignment of novice paratroopers to their first airborne unit ... a once in a lifetime event!
PRO rating :: A USPA qualification indicating competence to perform difficult demonstration jumps; such as the US Army Golden Knights and the US Navy Shooting Stars.
Provider :: The Fairchild short take-off and landing (STOL) light transport aircraft (C-123 USAF), powered by twin-engine turboprop, that was used in airlift, forward air control (FAC), flareship, and other military missions; nicknamed the "bookie bird", it was developed in 1949 from the aluminum-skinned XCG-20 twenty-passenger glider, this medium capacity transport is sized between the smaller C-7A Caribou, and the larger C-130 Hercules.
pud :: Slang for a soft handle, that's ergonomically designed for a comfortable grip and aerodynamically designed to be low-profile, used for various parachute operations, such as the handle on a pullout pilot chute system.
pullout / pull-out :: A pilot chute that is packed inside the container and is deployed by using a lanyard-connected handle, the pulling of which also releases the main canopy container retaining pin.
pull-up cord :: A piece of cord or length of line used to thread the closing loop through the grommets or eyelets of the packed container as an aid to closure, which cords are removed once the closing or retaining pins are inserted.
quick pin :: The quick-release aircraft assembly pin used to attach parts of a glider.
racetrack :: The oval or circular flight pattern used by aircraft when returning to an approach or recycling to an execution point, as when selecting the exit point or testing wind drift, and returning to the spot for parachutists to jump; formally known as an "Air Control Point" (ACP), this orbit is also called 'go-around'.
radiosonde :: An instrument that is carried aloft by a balloon to send back scientific information on atmospheric temperature, pressure, and humidity by means of a small radio transmitter.
ram-air parachute :: A "square" or oblong parachute with a canopy consisting of an upper and lower surface that is inflated by ram air entering through specially designed openings in the front of the canopy to form a gliding airfoil. These semi-rigid inflated airfoils may also be configured elliptically for higher performance.
rating :: The certified proficiency level of a parachutist. Civilian parachutists who present logbook authentication are rated "A license" when able to pack their main chute, self-jumpmaster, make water landings, and perform basic RW; "B license" when also able to night jump and participate in competitions; "C license" when also able to jumpmaster other licensed skydivers and make demonstration jumps; and "D license" when expert in all aspects, is eligible for instructor qualification and appointment as Safety and Training Adviser (S&TA). The USPA also rates 'jumpmaster', 'instructor', and 'PRO' demonstration jumpers. Military parachutists are eligible only while assigned on "jump status" to an Airborne unit and are rated 'basic' after student training and 5 static line (SL) jumps; 'senior' after jumpmaster training and 30 SL jumps; and 'master' after instructor training and 65 SL jumps. The 'Military Free Fall' (MFF) rating is restricted to "master" parachutists who are trained in skydiving specialties while assigned to a special operations force unit. An unofficial golden parachutist badge is presented to "master-blasters" who have completed 100 SL jumps, but this device is not authorized for wear on-duty. The USPA awards a golden parachutist badge to skydivers who have accumulated 100 hours of freefall delay, and a similar diamond parachutist badge for accumulating 1000 hours of freefall delay before chute deployment. Both the USPA and FAI qualify judges to evaluate skydiving competitions.
rawinsonde :: A method of upper-atmosphere meteorological observation conducted by means of a small radio transmitter (radiosonde) that's tracked by radar.
red hat :: A red-colored baseball-style cap emblazoned with rigger wings, to designate a parachute repairer or packer on the loading strip or drop zone (DZ). Also, a maroon-colored beret approved for wear by paratroopers on active jump status, as derived from WWII British Airborne units.
relative acceleration :: The variable speed of a skydiver in freefall, depending upon body posture and prevailing wind, as compared to the descent of others, as when linking or separating; this 'fall rate' measure is not an absolute calculation (terminal velocity) of speed.
relative wind :: The apparent wind felt by a jumper in freefall, which results from the skydiver's speed while passing through the air, regardless of the horizon. Also, the air that flows over the airfoil and jumper, or the glider and pilot in flight, which is created by movement through the airspace.
relative work :: The term formerly used to describe "Formation Skydiving" (FS); abbreviated "RW".
release pin :: A retaining pin, secured by tension, that's threaded through the eye of a stud or bolt, so as to be readily dislodged when deployment is actuated.
repair :: Any correction, reinforcement, reconditioning, or renewal to damaged gear, as by mending or patching, that restores its function so as not to adversely affect its weight, strength, structure, flight characteristics, or other qualities of airworthiness or performance; not a modification or alteration.
reserve :: The auxiliary, secondary, or backup parachute of slightly reduced dimension that is intentionally carried on every non-emergency parachute jump. An approved parachute worn for emergency use to be activated only upon failure of the main parachute or in any other emergency where use of the main parachute is impractical or use of the main parachute would increase risk. A reserve must comply with very strict standards, being inspected and repacked every 120 days by a specially licensed rigger, whether it has been used or not. Paratroopers, smokejumpers, and MFF-skydivers are required to wear front-mounted reserve chutes.
reserve ride :: The somewhat faster descent from a deployed reserve parachute, which is smaller and simpler, after the reason for its employment has been resolved.
reserve static line :: The connection from the main canopy risers to the reserve parachute release; abbreviated RSL. Formerly known as a "Stevens system" after its inventor.
reverse flight :: A non-flying canopy maneuver that collapses the canopy and may cause it to spin. This "full stall" results when the toggles are depressed beyond the "critical angle" until the trailing edge is lower than the leading edge. A "full stall" may result in an unrecoverable malfunction.
rib :: A vertical and longitudinal fabric membrane that forms the airfoil shape and primary structure of a ram-air canopy. Also, the shaped aluminum tube that slips into the flexible sail of a glider to form its airfoil shape; alternatively known as a 'batten'.
ridged harness / rigid harness :: In para-sailing, a rigid seating structure (gondola) that supports one or more occupants in a partially seated or semi-reclined position that combines gravity restraint with harness webbing to secure the occupant(s) into that structure, which is directly attached to the para-sail canopy; this arrangement allows the occupant(s) to evacuate themselves in case of an emergency.
ridge lift :: A soaring ascent resulting from the upward deflection of wind striking a ridge or other elevated impediment.
rig :: Slang for the entire parachute, including main and reserve canopies together with the harness/container and deployment mechanisms; the unit resulting from the combination of related elements. Also, to don or dress in full paragear; to "suit-up" for parachuting. Also, to adjust or modify the essential paragear for a particular jump.
rigger :: A Quartermaster specialist responsible for the supply, maintenance, and proper packing of various parachutes, including reserve, cargo, and personnel; such skill specialization has been distinguished since 1948 by wear of a red baseball-style cap ("Red Hats") and a unique qualification badge, which was finally approved on 9 June 1986.
rigger's certificate :: Certification by the FAA of a rigger's proficiency and competence. A rated 'senior rigger' may make minor repairs and pack reserve and main parachutes. A rated 'master rigger' may make major repairs and alterations as well as packing parachutes.
rigger's loft :: a spacious facility used for the inspection, packing, maintenance, and repair of parachutes; so-called from its galleried court configuration, with long tables and industrial sewing machines, being an expansive arrangement that's necessary for accommodating the exposed parachutes.
rip-cord / ripcord :: The deployment system on all reserves and most free-fall parachutes so as to enable descent; being a length of cable with a D-ring handle at one end and a release pin (or set of pins) at the other, so that when pulled, the pins come out of the closing loop holding the parachute container shut, and the spring-loaded pilot chute (tethered by a bridle to the main canopy) is thus released so as to open the main (or reserve) parachute for descent. Some rigs use pullout or throw-out pilot chutes.
ripstop nylon :: A fabric woven with a double thread approximately every quarter inch so as to prevent the expansion of small rips; fabric woven in an intermittent box form with additional closely-picked yarns.
ripstop tape :: Ripstop nylon fabric with a pressure-sensitive adhesive backing that's used to repair small tears in canopies.
riser / risers :: The webbing straps that connect the parachute harness to the suspension lines. At the end of the risers is a mechanism, such as Capewell, Chrysalis, or three ring release, for harness attachment and detachment. The brakes/steering control lines are affixed to the back or rear risers. The suspension lines attach to the top of the risers with connector links, which are also known as "rapid links". On older arrangements (without steering or control toggles), the canopy suspension lines are sewn directly onto the risers, making each riser responsible for the directional control of a fourth of the canopy.
riser dock :: In advanced canopy relative work, a momentum dock secured at the risers.
riser loops :: Loops or devices positioned on the front risers that make it easier to grip or grasp; also known as "grab loops", "blocks", "dive loops", or "front riser loops".
rocketsonde :: A telemeter for gathering data on the atmosphere at very high altitudes, carried aloft by rocket and returned to earth by parachute; derived as a blend of rocket + sonde.
rockoon :: A rocket probe launched from a balloon at high altitude for the collection of scientific data; derived (1950) as a blend of ROCKet + ballOON.
Rogallo wing :: A fully flexible wing with a stiffening structure that was patented by Francis and Gertrude Rogallo in 1951, becoming the semi-rigid airfoil configuration that was tested in 1957 by the National Aeronautics and Space Administration (NASA) as a recovery system for Gemini space capsules; it later inspired the commercial manufacture of foot-launched recreational hang gliders.
ROL :: The "rear of leg" position, which may be used as a pilot chute pouch location for throw-out manual deployments.
roll :: An axial plunge, swaying or rocking, as when alternating side to side banking or unbanking movements, as typically controlled by body posture. [cf: heel, list]
root :: The center or central section, as of a wing; the essential or fundamental part.
rotor :: A system of revolving airfoils, as the horizontal ones of a helicopter or of the compressor of a jet engine. Also, swirling air that's downwind of an obstacle.
rotor kite :: An unpowered rotary-winged airfoil that's tethered (by a kite line) for towing from a fixed or mobile mooring vehicle.
round :: A formation where each skydiver has grips on the arms of those next to him; also known as a "star". Also refers to a parabolic canopy or a round parachute, as opposed to a more modern ram-air "square" parachute; the average adult parachutist typically descends at 18 feet per second under a round-top.
RSL :: Reserve Static Line, being a connecting line (tether or lanyard) from the risers for the main canopy to the rip-cord cable release for the reserve parachute. In the event that the main is cut-away, it may pull the reserve pin; but this release system for malfunctions is only effective where the main is at least partially deployed. Formerly known as a "Stevens system" after its inventor.
running :: Flying a canopy with the ambient wind, which maneuver produces the greatest possible ground speed; as opposed to holding.
RW :: Relative Work, the term formerly used to describe "Formation Skydiving" (FS) until the nomenclature was changed by the International Parachuting Commission. In RW, skydivers attempt to go through a predetermined sequence of freefall postures and formations, identified as "#-way", often forming geometric patterns.
safety pin :: A retaining pin, secured by tension or by latch, that's threaded through the eye of a stud or bolt, so as to prevent dislodgement. [v: cotter / cotter pin]
Safety and Training Adviser :: A volunteer representative of the USPA, who attempts to disseminate information about safe practices, types of malfunctions, causes of accidents, teaching methods, instructional materials, and acts as a liaison between the USPA and DZ coaches and personnel. All S&TAs are D license rated and most are qualified "instructor" jumpmasters. Also known as "Safety and Training Officer" (S&TO).
sailplane :: A lightweight motorless glider (qv) with a high lift-to-drag aspect ratio.
sailwing / sail wing :: A single surface gliding parachute developed by David T. Barish in 1965, and manufactured by Parachutes Incorporated in Orange, Massachusetts. The pennant-like canopy material provided stability, with its bulk being about half that of contemporary parabolic canopies, yet the descent rate was about half (10-11 fps) of conventional rigs. The Barish sailwing came with single risers with Capewell riser releases on each side, had eight 1500 pound suspension lines, and had a safety stop steering system, which was designed to prevent accidental stalling of the canopy. The safety stops required only a five pound toggle pressure, afterwards necessitating an increase to 20-25 pounds of toggle pressure. Accuracy proved to be quite good, with two test jumpers making dead-centers on their first jump with the canopy. Opening shock of the sailwing is comparable to low porosity, flat circular canopies; and its forward speed is rated at20mph. The National Aeronautics and Space Administration (NASA) further developed this design for the recovery of space capsules.
sandbag :: Slang for any mandatory object or person, being obstructive or superfluous, so-called after its primary definition as ballast.
sausage :: slang for a sausage-shaped observation balloon, especially of the type formerly used in warfare.
scramble :: The term used in the 1960s for an informal gathering of skydivers, as distinguished from a formal competitive meet sanctioned by a sponsoring organization; usage later displaced by 'boogie'.
scratch :: To erase, strike-through, strike-out, cancel or eliminate something, such as a line of text or a name on a manifest, as by rubbing it out or obliterating it by drawing a line through it. Also, to withdraw a submitted entry from further consideration, as in a competition; to recall, rescind, or revoke from further proceedings. Also, being in conformity with a certain standard; adequate or satisfactory, as "up to scratch" or "up to snuff".
scratching :: Slang for maneuvering a glider or other airfoil in uplift currents while close to ground level terrain.
seal :: The small lead seal secured to the closing pin of the reserve parachute by a thin wire or red thread which indicates that the container has not been opened since the date marked by the rigger on the data card.
SEAWARS :: SEAWater-Activated Release System, being a control device that automatically releases an air crewmember from his parachute upon immersion into water; a similar lifesaving mechanism automatically inflates their flotation device.
semi-elliptical :: A composite variant with characteristics from both square and elliptical parachutes.
senior :: The intermediate rating for military parachutists requiring jumpmaster training and a minimum of thirty static line jumps, which qualification is oriented to vertical tactical operations.
Sentinel :: A type of "fail-safe" Automatic Activation / Opening Device (AAD/AOD).
Shawnee :: Boeing CH-21 transport and cargo helicopter, nicknamed the "Flying Banana".
shock cord :: An elasticized cord consisting of one or more rubber strands forming a core that's usually covered in a woven synthetic fabric sheath, the ends terminating in metal hooks or plastic clips, which is typically used to secure or restrain loose objects without the necessity of tying knots; developed (1919) in Germany for launching gliders and sail planes, it was renamed 'Bungee®' when introduced to America during the interwar period ... a multi-strand version is commonly called "octopus strap" or "occy strap".
shot bag :: A parachute packing tool consisting of a rectangular bag filled with loose shot that's used to temporarily hold folded gores in position during parachute assembly packing. [cf: Hacky Sack®]
shroud :: Informal reference to any of a number of cords or suspension lines of a parachute that attach the load from the harness to the canopy; also known as "shroud lines".
sideslip / side-slip :: To slide an airfoil sideways on a turn with a concomitant loss of altitude toward the inside of the curve, being the result of excess speed and improper angle of approach; also called a sliding or skid turn, and often shortened to 'slip'.
silken overcast :: See gang-bang.
SIM :: The Skydiver's Information Manual is a comprehensive reference on USPA policies and training methods, including the Federal Aviation Regulations (FAR) that are pertinent to skydiving.
single-harness dual-parachute system :: The typical one-person "solo" rig; being a combination of a main parachute, approved reserve parachute, and approved single-person harness and dual-parachute (tandem rig) container. This parachute system may have an operational automatic activation device (AAD) installed.
single operation system :: A single release handle (pud) simplifies the functions of the cut-away and reserve handles by combining them; abbreviated SOS. Refers to a parachute harness and container operation system with a combined single-point riser release and reserve rip-cord handle, such that pulling one handle will both release the risers and deploy the reserve in an emergency; as distinguished from a two-handled system.
single point release :: Also called a "clutch" or "cut-away handle", and includes the patented "three ring" release; may be abbreviated SPR.
sink :: A downward or dipping air current, especially one of gradual descent.
sit flying :: An upright vertical freefly orientation based on a seated posture, such as but not limited to 'chute assis'.
skin friction drag :: Aerodynamic resistance (commonly called 'drag') due to the contact of moving air with the outer surface of an airplane, a glider, and other falling bodies passing through air space.
skirt :: The reinforced hem that forms the periphery of a parachute canopy where suspension lines are attached.
skivvy folder :: Slang referent for a rigger.
sky blossom :: An informal allusion to a fully deployed parachute canopy; also called "blooming sky flower" or "falling down umbrella"; used as a referent for WWII paratroopers.
skyboard /-ing :: The combination sport of freefalling and skysurfing with a specially rigged "skyboard" already emplaced. The skyboard is a rigid panel, resembling a surfboard or snowboard, that attaches to the jumper's footwear.
skydive /-ing :: The controlled descent of a person exiting from an altitude to land at ground level, during which passage, the deployment of a parachute is delayed for a calculated period, measured in seconds, for the execution of maneuvers or the formation of patterns, usually as sport or recreation.
skydiver :: A parachutist who engages in skydiving; also called 'sport parachutist' or "freefaller".
Skydiver's Information Manual :: The comprehensive policy and training manual of the USPA, including pertinent Federal Aviation Regulations (FAR); abbreviated "SIM".
skygod / sky god :: Ostensibly and superficially, a superior parachutist; but actually a jumper with an ego greater than his ability. This derogatory or dismissive appellation serves as a warning to others on the DZ that this skydiver may be uncooperative, incompetent, or hazardous to fellow jumpers sharing the same sector of sky.
skyhook :: A grab line, suspended either vertically or horizontally, that enables a passing aircraft to snag or snatch it so as to engage the towline that's connected to a package, either human or inert, for expedient aerial extraction. [cf: trawl]
skying out :: Slang term for an ascending parachutist or glider pilot who soars high enough to virtually disappear from ground observation; also called "specking out".
Skymaster :: Cessna O-2 fixed-wing aircraft, with two propeller engines, one fore and one aft of cabin section in split tailboom, also called "Mixmaster" and "push-me-pull-you"; being a short take-off and landing (STOL) used on forward air control (FAC) and visual reconnaissance (VR) operations.
sky shark :: Slang for An unrelated (hence, unwanted) airplane flying in the drop zone area; a potentially troublesome or hazardous interference with freefall procedures.
skysurfing :: The combination sport of freefalling with a specially rigged "skyboard" already emplaced. The skyboard is a rigid panel, resembling a surfboard or snowboard, that attaches to the jumper's footwear.
Skytruck :: (forthcoming)
Skyvan :: (forthcoming) tailgate 22 skydivers on a jump run
SL :: The abbreviation for static line (qv).
sled run :: Slang for a ground-based launch that does not entail enough lift to sustain the flight of a glider or other airfoil; an ironic characterization.
sleeve :: A tapered fabric tube in which the canopy is placed to control its deployment; also called bag, deployment bag, or pack sack (qqv).
slider :: A rectangular piece of nylon fabric with a grommet at each corner through which the main canopy's suspension lines are routed on a square-top. Packed at the top of the suspension lines, the slider controls the progressive opening of the ram-air canopy by preventing the parachute from expanding too rapidly; if the slider descends too slowly, it can cause a malfunction by inhibiting the canopy from filling completely. A "collapsible slider" may be compressed or wrapped by the jumper after deployment to reduce drag. The purpose and function of a slider is similar to a diaper on parabolic canopies.
Slinks :: A type of Spectra fabric connector link developed by Performance Designs Inc, for attaching the lines of the parachute to the risers.
slip :: A movement, most often performed as a "sideslip", intended to abruptly steer a parachute away from (or toward) an object or obstacle by pulling the risers as far down as possible. In mass airborne assaults or in hazard landings, the risers will have been pulled all the way down to the jumper's feet. Also known as "grabbing line", from the practice of pulling the risers as if climbing up the suspension lines until the canopy could be mounted! Also, in glider maneuvering, an uncoordinated turn that results in high airspeed and a rapid sink rate.
slipstream :: The "burble" of turbulence generated by an object passing through air or space, as the airstream or backwash (wash) around an aircraft from its propulsion. Also refers to the pocket of reduced air pressure and forward suction generated behind a moving object, craft or vehicle.
slipstreaming :: Introducing something into an existing flow or an ongoing process so as to fully integrate it, or to bring it up to full speed with the least friction or resistance. [v: kinetic energy]
slope soaring :: A flight activity, also called 'paraglide' or 'parapente', involving the use of an airfoil or a ram-air inflated wing in foot-launched surface lift-off gliding, which was promoted by David Barish as a summertime activity for ski resorts.
slot :: A position in the skydive formation or on the jump plane; used as "dock in your slot" or "two slots left on the next bird".
smokejumper :: A skydiver certified for both firefighting and "rough terrain" parachuting, employed to control forest fires in remote settings by federal agencies (ie: Forest Service, Bureau of Land Management) or regional fire departments. Originating as firemen who literally "free jumped" (without a parachute) out of small airplanes in a temporary stall at low altitude onto a remote clearing near a forest fire, they experimented with parachutes until they could adapt the techniques to their settings. The smokejumper's parachute landing fall (PLF) still retains the rolling tumble developed in the "free jump" days. The first operational parachute jump by smokejumpers was made on 12 July 1940 in Idaho. Smokejumpers wear protective facemasks on their helmets, and their jumpsuits are both fire- and puncture-proof. Special operations forces use the "rough terrain" jump school as preliminary training for further military specialization.
soar / soaring :: To fly upward; to rise or ascend to a height, as by uplifting currents. Also, to fly or glide along at a height by use of an airfoil; to traverse the skies high in the air.
Soft Landing Assembly :: A ram-air parachute modified by the addition of safety features that reduce the risk of the parachutist landing too fast or too hard; an innovation developed in 2001 by Richard J. Benney and Glen J. Brown, with the patent assigned to the U.S. Army on 10 June 2003. At the top, the parachute has a bridle with an extra loop of line on either side and an electrical cutting mechanism to release it; in the middle, it has a "pneumatic muscle" for reconfiguration; and there's an automatic altitude measuring device that calculates when the safety mechanisms need to be deployed by projecting radar beams at the ground to continuously measure the parachutist's height and speed.
solar sail :: An aerospace design concept proposed (1955) for spacecraft propulsion that consisted of a very thin, very large sheet of highly polished material that would be driven by the pressure of sunlight, and that could, therefore, impel a suitable spacecraft.
solo :: A skydiver who uses a single-harness dual-parachute system.
sonde :: An observation balloon, rocket or rockoon used as a probe for collecting scientific data or atmospheric phenomena; as derived from 'plumb line'.
SOS :: Single Operation System, which simplifies emergency procedures by combining the functions of the cut-away and reserve handles into a single handle. Also, Skydivers Over Sixty, acronym for the worldwide association of superannuated skydivers and parachutists (1992). [v: POPS]
span :: The dimension of a wing or airfoil measured from tip to tip.
SPC :: Sport Parachute Club; the local or regional organization of civilian skydivers, usually affiliated with USPA.
Spectra® :: The material from which 'microline' is made.
speed bar / speedbar :: A specially curved base tube that allows the pilot of a hang glider to pull in farther with less discomfort than with a straight base tube.
spill :: To fall in an uncontrolled manner during a parachute landing; a landing that does not use or improperly uses a parachute landing fall (PLF), risking injury to the person and damage to the equipment. Also refers to the rapid or abrupt dumping of air from the canopy, as in a slip (qv).
spiral :: The profile of an airfoil when sustaining a given bank angle during an ascending or descending turn; departure from such consistency (eg: slip) is characterized as "spiral instability".
spiral dive :: A deliberate high-speed slip that causes a glider or other airfoil to rapidly descend while banking away from a powerful updraft current.
splash :: Slang reference to a water landing, whether accidental or intentional.
spoiler :: A device used to break up the airflow around an aerodynamic surface, such as an airfoil or wing, so as to decrease its lift and to provide bank or descent control.
sport parachute /-ing :: The phrase used for recreational and competitive parachuting employing modified or steerable chutes; as distinguished from military operations, in full gear and bad weather.
sport parachutist :: A skydiver; a recreational or competitive jumper.
spot :: The position of the aircraft when the jumpers exit. Selecting the spot ("spotting") is the responsibility of the jumpmaster, loadmaster, instructor, or coach in coordination with the pilot. A stable or solid spot can facilitate jump maneuvers or simply enhance the pleasure of a jump. Also called "jump spot", "initial point", "launch", and "point of departure".
spotter :: A jumpmaster or crew chief who designates the jump spot, exit point, and drop zone (if not previously selected) for the parachutists; the spotter usually remains aboard the aircraft to observe the descent and report its outcome. Sometimes called a "monitor".
spotting :: Selecting the jump run course, advising the pilot of course corrections, determining the ground reference point (exit point), and designating the jump spot preparatory to departure of the aircraft.
spread eagle :: A stable, face-to-earth body position in which the back is arched, the arms and legs are straight, and the limbs form wide v-shaped angles for maximum exposure. This arched X posture, which is also called "starfish", is useful as a recovery body position and as a pre-deployment body position.
square :: Slang for a rectangular ram-air parachute, being a pressurized wing that actually "flies" instead of just inhibiting descent with the drag of a "round" parabolic canopy; the average adult parachutist typically descends at 12 feet per second under a square-top. These semi-rigid inflated airfoils may also be configured elliptically for higher performance.
squirrel suit :: Truncation of "flying squirrel suit"; see wing suit.
S&TA :: Safety and Training Adviser (qv).
stability :: The control of body posture, position, and maneuver during freefall, such that any alterations are voluntary and productive; a stable freefall position for the planned execution of controlled movements.
stabilizer :: The vertical strips of cloth descending from the end cells of the ram-air canopy, which are designed to improve the canopy's ability to fly straight ahead and to enhance efficiency by reducing tip vortices.
stack :: A vertical canopy formation with the jumpers gripping the canopy or lines just below the canopy. Also, the vertical alignment of tactical parachutists, formed in trail, in preparation for sequential landings onto a confined or delimited drop zone (DZ).
stall :: The state of canopy flight control characterized by decreased glide and increased rate of descent; as when the angle of attack of a wing or other airfoil becomes too high to sustain lift, and momentarily hesitates before losing its aerodynamic properties, resulting in a downward spiral or spin. A parachutist deliberately stalls with an air-braking flare to achieve a low-impact "stand-up" landing when close to the ground.
static line :: A line, cable, or webbing strap designed to automatically open a container or release a canopy when the person or load falls away from the aircraft and reaches its end. In static line parachuting, the webbing line, measuring about fifteen feet long, is anchored to the airplane with the trailing end attached to the release pins of the parachute, resulting in automatic deployment after about a four or five second delay. Paratroopers, who are thus characterized as "dope on a rope", use this technique on all jumps, but skydivers pass through this stage, after learning rip-cord pulls (DRCP), practice deployments, parachute control, and landing techniques, to eventually master freefall techniques.
static line jump :: A parachute jump that uses a static line to deploy or partially deploy the main canopy; as when training student skydivers.
steering lines :: The guide or control lines that run from the steering toggles on the rear risers to the trailing edge of the sport parachute.
steering toggles :: Loops or cylindrical handles attached to the ends of the steering lines of a parachute canopy in order to facilitate their use. Toggles and lines are configured so they can be stowed in a partially down position to enhance the opening of the parachute.
step-through :: See thread through.
Stevens system :: The original reference for a "Reserve Static Line" (RSL) connection between the main canopy risers and the reserve parachute release, which is automatically actuated during a malfunction cut-away if the main has developed sufficient drag. Also called "Stevens connection" or "Stevens automatic"; was superseded by the "Single Operation System" (SOS).
stick :: The file of paratroopers which conforms to the size of the jump aircraft, regardless of their regular table of organization and equipment (TO&E) assignment; may include "inboard" and "outboard" sticks. The number of paratroopers who jump from one aperture or door of an aircraft during one run over a drop zone.
stick commander :: The qualified person who is designated to be responsible and in control of a stick of paratroopers from assembly through enplaning to exit; sometimes called "mother hen".
S&TO :: Safety and Training Officer; see Safety and Training Adviser (S&TA).
stow :: To neatly arrange the suspension lines on the deployment bag and to place the steering toggles in their keepers.
strap-hanger :: Slang for an extra person not attached or officially assigned, as a supercargo or supernumerary, including anyone who wants to do the job just for the experience, as well as those ubiquitous hitchhikers and BLOBs.
streamer :: A total parachute malfunction, in which the suspension lines are wrapped around the canopy so it cannot deploy; also called "twister" and "cigarette roll". If the reserve chute is deployed before the main is cut-away, the new canopy will join the malfunction of the primary canopy, and the parachutist will fall to his death without perceptible deceleration.
student :: A trainee or novice learning the rudiments of parachuting, especially a skydiver without a rating or license.
style :: A type of freefall competition where an individual skydiver attempts to precisely execute a predetermined sequence of maneuvers in the shortest possible time.
suspension lines :: The cords extending from the risers to the canopy. On round-tops, they are distributed equidistant around the canopy perimeter at the ribbed gutters of the skirt; and on square-tops, they are normally gathered into four groups (A-D), and divided into right and left or front and back riser groups, with or without cascading. The type of line material may be either the thicker but softer Dacron polyester or the smaller Spectra "microline". Suspension lines are the means by which the weight load of the person or cargo is borne by the inflated canopy.
sustained wind speed :: A calculation determined by averaging the observed wind speed over a two-minute period, and rounding the result to the nearest whole knot.
sweep / swept :: Driven or carried by some steady force, as of wind. Also, the position of wings such that their tips trail behind the aircraft's nose, so as to aid the stability of pitch and yaw during flight.
swoop :: To quickly dive to link with an individual in freefall, or to quickly dive into an assigned slot in a formation. Also refers to rapidly approaching the landing area so as to create a dramatic landing with a long flat flare.
swoop pond :: A water obstacle, also called a "swoop ditch", used as a high-performance demonstration landing area.
tab :: A small flap, strap, loop, or similar appendage, as on a pack or suit, used for pulling (eg: trim tabs), grasping (eg: grippers), or hanging (eg: cross connectors). Also, a small airfoil hinged to the rear portion of a control surface, as to an elevator, aileron, or rudder. Also, a distinguishing label (arc) denoting qualification or proficiency, as worn on a hat or sleeve.
tandem :: A parachute jump in which two skydivers, usually an instructor and student, share one parachute system; the student wears a separate harness that attaches to the front of the instructor's harness. The canopies are typically oversized. The jumpers are also designated "passenger" (front) and "command" (rear); also called "piggyback". This is one of the AFF/IAD techniques.
tandem parachute system :: The combination of a main parachute, approved reserve parachute, and approved harness and dual parachute (tandem rig) container, and a separate approved forward harness for a "passenger parachutist". This parachute system must have an operational automatic activation device (AAD) installed.
tandem rig :: A parachute harness/container configured so that both the main and reserve canopies are serially mounted on the jumper's back. This "dual assembly" is a more comfortable and convenient configuration for civilian parachutists, but requires the use of either a reserve static line (RSL) or a single operation system (SOS). Paratroopers, smokejumpers, and MFF-skydivers are required to wear front-mounted reserve chutes.
target :: The specified landing area on a drop zone; which, in officially sanctioned competitions, is a three-centimeter disk at the center of graduated distances for grading accuracy.
Technical Standard Order :: A Federal Aviation Administration (FAA) regulation (TSO-C23), including National Aircraft Standard (NAS), requiring parachute manufacturers to comply with minimum performance standards and material product specifications to ensure safety; TSO compliance must be certified on a product display placard in order to be legally marketed.
telltale :: A weighted streamer used to check wind speed and direction; also called 'wind drift indicator' (WDI).
terminal velocity :: The speed at which atmospheric drag counterbalances the pull of gravity on a falling object in a stable posture, resulting in a constant fall rate; a spread eagle body falling at its maximum acceleration, given the resistance of air density on the size and weight of the falling object. The typical freefall equilibrium velocity attained against air resistance is approximately 160 - 200 fps (or about 110 - 130 mph) for the stable face-to-earth body position; but speeds as high as 300 miles per hour have been reached.
thermal :: A rising air current that's caused by heating from the underlying surface, especially such a current in the lower atmosphere when not producing a cloud.
thermal column :: A stack of rising air (atmospheric convection) created by the uneven heating of earth's surface from solar radiation, which entails a downward flow of displaced cooler air surrounding the thermal column.
thread through / thread-through :: A leg strap configuration on a parachute harness that uses a single piece of adjustable hardware, such that leg strap disconnection would require complete disassembly or "unthreading"; also called "step-through". When donning or doffing this parachute harness, the jumper simply steps into or steps out of the connected legs straps.
three ring :: A parachute release mechanism connecting the risers to the harness. This cut-away release system, invented by Bill Booth in the late 1970s, utilizes three rings of separate size in a mechanical advantage mechanism. In its common configuration, pulling one cut-away handle will simultaneously release both main risers. It is a patented form of "single point release", also available in a scaled-down "mini three ring" release version; and replaces the older style Capewell and Chrysalis releases.
throw-out :: A hand deployment method for parachute activation in which the pilot chute is stowed in a pouch on the belly (belly-band) or leg (ROL), or bottom of the container (BOC), and introduced manually into the airstream. A curved closing pin or equivalent locking device on the bridle is extracted as the jumper is separated from the pilot chute, opening the container and deploying the main canopy. A bridle tethers the pilot chute to the main canopy.
toggles :: Loops or cylindrical handles attached to the ends of the steering lines on a parachute canopy in order to facilitate their use; also called "steering toggles". Toggles and lines are configured so they can be stowed in a partially down position to enhance the opening of the parachute.
tow-bar / tow bar :: The mechanism that connects the towline tether to a para-sail harness system.
towing yoke :: The webbing area where the towline and tow-bar attach to the flexible body harness and riser straps, including the canopy and towline quick release mechanisms.
towline :: A relatively non-elastic line, rope, cable, hawser, or the like, by which anything is (or may be) drawn, pulled, hauled, or launched. In para-sailing, a low-stretch double-braided polyester rope suitable for winching that connects the mooring platform to a para-sail system.
towline guide :: An upright structure near the winch that swivels so as to support the series of pulleys and rollers of the deployed towline tether.
towline quick release :: A disconnect device that may be actuated from either the towing vehicle or the towed object, as a normal method of deployment or as an emergency modality to preserve lives at unanticipated risk.
tow plane :: An airplane towing one or more gliders, as for launching; also called "tug ship", "air train", or "sky train".
track :: The body position or movements designed to achieve the maximum horizontal speed in freefall. The general term for the aerial maneuvers that skydivers use to laterally approach and depart other jumpers. Specifically, these versatile, face-to-earth body positions enable the skydiver to move tangentially or peripherally, forward or sideways, by the angle of the head, the retraction of arms or legs, or the extension of arms or legs. These same maneuvers, when extended into aerobatic routines, constitute the discipline of freestyle performance.
trailing edge :: The rear edge of a moving object, especially a propeller blade or airfoil. Also, the rear edge of an air mass.
trim tabs :: A front riser pulley system for adjusting a ram-air canopy's or airfoil's angle of incidence or flight attitude.
TSO :: Technical Standard Order (TSO-C23) is a Federal Aviation Administration (FAA) regulation, including National Aircraft Standard (NAS), requiring parachute manufacturers to comply with minimum performance standards and material product specifications to ensure safety; TSO compliance must be certified on a product display placard in order to be legally marketed.
tuck :: Slang for the body posture commonly called 'frog' (qv).
tug ship :: See tow plane.
turbulence :: Disturbed air that can adversely affect canopy flight and integrity. Also, the disorderly effect of irregular and inconsistent motions. Also, the haphazard secondary motions caused by eddies within a larger moving medium, as in the gusts and lulls of winds aloft in the atmosphere.
turf surf :: To run with the wind in ground effect; a sustained high-speed paraglide across and slightly above ground level, before using a flaring hook turn to land spectacularly.
turn around load :: The quick pick-up of jumpers into a plane that does not shut-down after landing, so as to immediately take-off again for another jump run.
turn slots :: The vent openings situated at the sides of a gliding parachute canopy through which air is expelled, enabling the parachute to be steered to the left or right while providing stability.
Twin Beech :: (forthcoming); Beechcraft
Twin Otter :: (forthcoming); DeHavilland (DHC) fast and reliable with large door for serving 20 skydivers on a jump run
two-handled system :: Refers to a parachute harness and container operating system that uses separate handles (pud) for the canopy release and for reserve activation; as distinguished from a Single Operation System (SOS).
ultralight :: A lightweight single-seat motorized glider with an exposed (deformable structure) fuselage, which the Federation Aeronautique Internationale (FAI) categorizes by its maximum weight; the ultralight sailplane (essentially a motorized hang-glider) is also known as a "microlift glider" or "airchair". [nb: some countries do not require licensure for pilots to fly an ultralight aircraft]
uncouple :: To release the connecting link between objects or persons; the mechanical disconnect or physical separation of a coupling; to unfasten or let go, as a parachute uncoupled from its harness, or a glider uncoupled from a tow plane.
undercast :: A cloudy overcast seen from above.
undercurrent :: An air current that flows below the upper or beneath the primary currents.
unpowered aircraft :: Those aerial vehicles that can fly without onboard propulsion, including the heavier-than-air glider / sailplane, hang glider, balloon, paraglider / parapente, parawing, and kite; the launch process imparts initial energy to motorless airfoils but sustained flight derives from acquiring additional lift and momentum from the dynamic action of wind conditions aloft upon the lifting surfaces of the airfoil.
updraft :: The ascending flow or movement of air, or other rising gas.
uppers :: The upper winds, or the winds blowing at exit altitude, which are often much stronger and occasionally from a different direction than ground winds. Also called "winds aloft".
upwash :: The slight updraft, or upward flow of air that's redirected just prior to its reaching the leading edge of a rapidly moving airfoil.
upwind :: The direction from which the wind is blowing; toward or against the prevailing wind.
USHGA :: The abbreviation for United States Hang Gliding Association.
USHPA :: The abbreviation for United States Hang Gliding and Paragliding Association, being a membership organization that rates glider pilots and certifies soaring instructors.
USPA :: The United States Parachute Association is a non-profit skydiver's membership organization offering guidance and assistance in training, competition, government relations, insurance, and other appurtenances. It originated in 1957 as "Parachute Clubs of America" (PCA), the coordinating body for autonomous and regional sport parachute clubs (SPC), and as a division of the National Aeronautic Association (NAA), it is the official representative of the Federation Aeronautique Internationale (FAI) for skydiving in the USA.
vario / variometer :: An instrument that indicates the rate of ascent or descent, as related to vector changes in the earth's magnetic field; an instrument that measures the vertical speed of a glider's sink or climb.
veer :: A change of direction, course, position, or attitude, as when turning aside, or shifting into the wind.
vent :: (drive slots, turn slots; port)
volplane :: To glide toward the earth in an aircraft with no motor power or with the power shut off.
VOR :: Very-high-frequency OmniRange, being a fixed VHF radio bearing that functions as a navigation reference point to aid the pilot in ascertaining exact location.
vortex :: A whirling mass of air, especially one in the form of a visible spiral, and operating with the force of suction, as a tornado.
waffle :: The vibratory effect of a canopy or airfoil during an abrupt brake or sustained flare, in which the leading edge trembles or flutters, and the entire surface may ripple or undulate, as the parachute attempts to resume flight. An effect similar to luff, but from a different cause.
waiver :: A liability release. Also, an exception to the regulations authorized by the USPA. [nb: not to be confused with "waver": the quaking condition of frightened neophytes!]
wash :: To flow against, around, over, or through, as when currents affect passing crafts or vessels; also known as prop wash or jet stream (slipstream). Also, the rough or broken current (burble) behind a moving craft or vessel; a wake or backwash.
water jump :: A freefall or parachute jump that terminates by intentionally landing on the surface of an "open body of water".
wave off :: After break off and prior to deployment, a skydiver should check his surround, move away from other parachutists, and make a clearly defined arm motion to indicate to anyone nearby that he is about to open his parachute. A good wave off is essential to the avoidance of deployment collisions.
WDI :: Wind Drift Indicator; being either a weighted foil or crepe paper streamer that's thrown from the jump plane to estimate winds under canopy and to help determine the jump spot; also known as a 'telltale'. The military will also use a flagged smoke grenade as WDI, but the best indicator is a pathfinder on the DZ.
weights :: Many light- or underweight civilian skydivers wear a weighted vest to allow them to maintain a fast fall rate; but military parachutists, who almost always jump with equipment, do not have this problem.
winch :: An hydraulically powered towline launch and recovery mechanism consisting of a support frame, winch spool, and level wind device.
winch boat / winchboat :: A special purpose towing platform at the stern of a vessel for launching and retrieving a para-sail skier, including a rotating line guide, release brake, pulleys and winch, towline and gliding parachute; the mooring vessel and rig being regulated and subject to inspection by the U.S. Coast Guard.
winch spool :: A cylindrical mechanism onto which a towline is wound.
wind drift indicator :: A device used to determine the amount and speed of wind drift which a descending parachute will experience on a particular drop zone (DZ) under the conditions that are currently prevailing. The WDI is constructed so as to descend at a rate comparable to a parachutist of average weight, or an object of average payload, descending under a fully deployed main canopy of average specifications. Usually, the WDI is a weighted strip of foil or brightly colored crepe paper ten inches wide by twenty feet long, but smoke grenades are also used.
wind line :: An imaginary line from the desired landing area, extending along the direction the wind is blowing to the point of release, or to the jump spot.
wind shear :: A dangerous condition in which the speed or direction of the wind changes abruptly. Also, the rate at which wind velocity changes from point to point in any given direction.
wing area :: The number of square inches (or square feet) of the wing; it's the wingspan multiplied by the wing's chord. The area of a tapered wing is the wingspan multiplied by the average chord.
wing loading :: The ratio (ie: pounds per square foot) of weight borne by a wing or airfoil to its surface area; obtained by dividing the jumper's exit weight in pounds by the square footage of the fully opened canopy. Excessive wing loading causes 'blow-outs', which can cause the canopy to fail as a decelerator.
wingspan :: The distance between the wingtips of an aircraft, glider, or airfoil; wingspread.
wing suit :: A gliding jumpsuit designed with fabric membranes between the legs of the jumper and from each sleeve to the torso. Derived from jumpsuits designed with extra fabric pleated into the sleeves and legs, thus varying the amount of drag by adjusting the amount of fabric wing exposed when released by zippers prior to the freefall exit. Also called a "flying squirrel suit", and often truncated to just "squirrel suit".
wing wiper :: Slang for aviation support staff and ground crew, as used by Navy and Marine aviators since before WWII; also known as "penguin".
wiresonde :: An instrument carried aloft by a captive balloon and sending high altitude temperature and humidity data over a wire cable; derived as a blend of wire + sonde.
wuffo / whuffo :: Skydiver slang for people who don't parachute; as derived from the groundling's or landlubber's most prevalent question: "Wuffo you jump outta dem planes?"! This term is considered "insensitive" by legs and other assorted landlocked sympathizers.
X-C :: The abbreviation for cross-country, which entails extended soaring flight (more than ten miles) to some distant point.
yaw :: The rotation of an aerodynamic body about its vertical axis so as to cause its longitudinal axis to deviate from the heading or flight line in its horizontal plane; the existence of an angle between the longitudinal axis of a projectile at any moment and the tangent to the trajectory in the corresponding point of flight of the projectile. The deviating motion or axial oscillation of a body in free flight from its straight course or stable attitude.
yo-yo :: An elevator-effect upon a deployed canopy (and the attached parachutist) generated by thermals and other turbulent or inconsistent air currents, especially when soaring over ice or fire, forest or sea, cliff or canyon.
zero-p / ZP :: Common slang ("zero-permeability") for a type of fabric that's relatively impermeable to air. The less air that flows through the fabric wing of a ram-air parachute, the more efficiently it flies.

In a world where we are all enslaved by the law of gravity, I proudly count myself as one of those defiant freedom fighters who boldly resist its dominance by skydiving!
anonymous

If riding in an airplane is flying, then riding in a boat is swimming ... you can only experience the true elemental medium if you get out of your vehicles.
anonymous

When Alice falls down the rabbit hole in Wonderland, and her dress poofs-up like a parachute to save her, she resolves that she will henceforth think nothing of tumbling down stairs or tripping off cliffs. It must be her destiny to be spared.
anonymous

Life is like a parachute jump: you assess the risks, are impressed by the view and thrilled by the adventure, but you carry along a reserve, just in case ... and even then, it's sometimes disasterous.
anonymous

A chance is what you take before you can think about it; but a risk is calculated ... it's what you take after you have evaluated all possible factors and have determined the potential harm or benefit.
paraphrase of Craig Elliot

Aviation is not in itself inherently dangerous, but to an even greater degree than the sea, the sky is terribly unforgiving of any carelessness, incapacity, or neglect.
anonymous

We regard religion in the same way that an airman regards his parachute: it's there for emergencies, but we hope that we'll never have to use it.
paraphrase of C.S. Lewis

Minds are like parachutes: they only function when they are open.
paraphrase of James Dewar

When you entertain the idea of soaring, you must also embrace the concept of falling, in the same way that life entails death and joy entails sorrow ... they're inextricably connected.
paraphrase of Richard Paul Evans

Any fool can fall out of an airplane, but skydivers do it right.
anonymous

Once upon a time sex was safe and skydiving was dangerous ....
anonymous

When the people look like ants – PULL!
When the ants look like people – PRAY!
skydiver's maxim

Always remember that out of ten-thousand feet of freefall, it's the last half inch that will hurt ... but only momentarily.
paraphrase of Charles W. Purcell

It's not the fall that kills you, but the sudden stop at the end!
anonymous

Just because nobody complains doesn't mean that all parachutes are perfect.
by Benny Hill

Man with unchecked parachute will jump to conclusion.
Chinese fortune cookie

Both optimists and pessimists contribute to our society: the optimist invents the airplane and the pessimist the parachute.
paraphrase of G.B. Stern

Paratroopers never die ... they regroup on Hell's drop zone and call the Devil to attention!
airborne maxim

We don't stop skydiving because we grow old; we grow old because we stopped skydiving!
by Bill Wood, motto of Parachutists Over Phorty Society (POPS)

Only skydivers know why the birds sing.
anonymous

Everyone can see their horizon, be it near or far, but few will ever reach it ... and even fewer will go beyond it into the forever changing sky.
anonymous