United States Parachute Association > Experienced Skydivers > SIM > Glossary




A&P:Acronym. 1. Assemble and Pack, Used on reserve parachute packing record cards. 2. Airframe and Powerplant Mechanic.

A LICENSE:  The first level license which signifies that a skydiver has advanced beyond the student phase. Persons holding a USPA A License are able to jumpmaster themselves, perform basic group freefall jumps and water jumps, participate in certain USPA collegiate competition events, and pack their own main parachute.


Accelerated Freefall (AFF), USPA:  Harness-hold freefall skydiving student training discipline developed under Ken Coleman and adopted by USPA. AFF-rated USPA Instructors accompany the student in freefall during the initial training jumps.

AGL:  Above ground level. Refers to altitude, e.g., 5,000 feet AGL.

Air Speed:  The speed of an airborne aircraft or parachute, relative to the air.

Aircraft:  Any machine or device, including airplanes, helicopters, gliders, balloons, etc., capable of atmospheric flight. For the purposes of regulation, parachutes are not considered aircraft.

ALTERATIONS:  Any change or modification to any part of the parachute assembly from its original manufacturer’s specifications. (see also MAJOR ALTERATION and MINOR ALTERATION)

ALTIMETER:  A device that measures height above the surface (altitude); for skydivers, typically above the intended skydiving landing area. (see also AUDIBLE ALTIMETER)

Angle Flying:A degree of back/belly flying that has a steeper angle than tracking used at breakoff. (achieving maximum horizontal separation or lift). This angle is much steeper but not fully vertical (straight up and down).

Angle of ATTACK:  The relative pitch (leading edge up or down) angle of a wing measured between the chord line and the relative wind.

Angle of INCIDENCE:  The relative pitch (leading edge up or down) angle of a wing measured between the chord line and the horizon.

Approach angle:  (see GLIDE PATH)

Appropriately Rated:  adj. Refers to a USPA Instructor or Instructional Examiner rated in the method-specific instructional discipline necessary to perform a particular task in accordance with the BSRs.

Arch:  n. Position skydivers use to orient the front of their torso to the relative wind. Described, it is hips forward with back arched; legs extended to 45 degrees, toes pointed; knees at shoulder width; arms bent 90-120 degrees at the shoulders and elbows and relaxed; head up.

Artistic Events:  Skydiving competition events that include freeflying, freestyle skydiving, and skysurfing.

AS 8015 (Aerospace Standard 8015):  Standard of tests and minimum safety and performance requirements which must be met to receive approval under technical standard order (TSO) certification. AS 8015A, the standard for TSO C-23c was adopted in 1984 to supersede NAS 804, the standard for TSO C-23b. In June 1994, AS 8015B became the standard for TSO C-23d.

Aspect Ratio:  The aspect ratio of a ram-air parachute canopy is the ratio of its length (span) to its breadth (chord).

Assisted Deployment:  Refers to a pull sequence prompted or cued by the instructor where the student begins the sequence and is completed by the student but may be assisted by the instructor.

Audible Altimeter:  An alarm used by skydivers to alert them about reaching one or more pre-set altitudes.

AUTOMATIC ACTIVATION DEVICE (AAD):  A self-contained mechanical or electro-mechanical device that is attached to the interior of the reserve parachute container, which automatically initiates parachute deployment of the reserve parachute at a pre-set altitude, time, percentage of terminal velocity, or combination thereof. (FAR 105 definition)



B LICENSE:  The second level USPA license. Persons holding a USPA B License are authorized to participate in the USPA collegiate 4-way formation skydiving event, perform night jumps, and when qualified, apply for a USPA Coach rating.

B.A.S.E. Jumping:  An activity involving the use of a parachute for descent from fixed objects. The acronym derives from the first initials of four possible launch categories:   buildings, antennae, spans (bridges), and earth (cliffs). Because BASE jumping does not meet the FAA’s definition of “the descent of an object to the surface from an aircraft in flight,” it is not regulated by the FAA or addressed by USPA.

B-12s:  (jar.) Clip hardware sometimes used for leg-strap attachment on a parachute harness. Refers generally to the MS 22044 hardware originally used on the U.S. Army B-12 parachute assembly. (see THREAD-THROUGH)


Bag Lock:  n. A malfunction of a deployed parachute where the canopy remains in the deployment bag.

Barrel Roll:  A maneuver in which a skydiver rolls about their longitudinal axis.

Base:  n. 1. When building a freefall or canopy formation, the initial target individual or group of people to which the others fly. 2. Base (leg):   n. The portion of the three-legged landing pattern where the jumper flies across the direction of the wind downwind of the landing area before turning for final approach into the wind toward the target.

Basic SAFETY REQUIREMENTS (BSRs), USPA:  Minimum standards overseen and published by USPA and generally agreed upon as the acceptable standard for safe skydiving activities. The BSRs form the foundation of self-governing by skydivers. USPA oversees the BSRs.

Belly Flying:  (see FLAT FLYING)

BOARD OF DIRECTORS (BOD). USPA:  Those representatives elected by the general members of USPA every three years as set forth in the USPA By-Laws; authorized by the by-laws to have general charge and control of the affairs, funds, and property of the organization and to carry out the objectives of the organization and its by-laws; elects officers from among current USPA Board members. The USPA Board of Directors consists of:   1. National Directors—those directors elected at large by the general membership; 2. Regional Directors—those Directors of a specified geographical area, elected by and responsible for representing the interests of the skydivers in a USPA Region; and 3. An ex officio member representing the National Aeronautical Association.

BRAKE FIRE:A premature brake release during the canopy deployment.

Braked Turn:  A turn under an open parachute canopy made by using the steering toggles to slow the forward speed of the canopy and then allow one side to fly slightly faster to change heading. Used to reduce altitude loss in a turn.

Brakes:  n. 1. The steering controls of a ram-air parachute. (see also TOGGLES) 2. n. The position of the parachute steering controls, measured in relative increments (quarter brakes, deep brakes, etc.), to control speed and descent in a stable state of flight.

Break Off:  v. Act of a group of jumpers separating from a freefall or canopy group.

Breakoff:  n. Procedure in group skydiving where jumpers cease group activity and separate. In freefall, jumpers begin to track at a predetermined altitude for a clear area to open safely; jumpers building canopy formations break off at a predetermined altitude to gain safe separation and allow jumpers to prepare for a landing approach.

Breakoff Altitude:  Planned altitude for initiating separation of jumpers during a group jump.

Bridle:  n. The device, usually made of webbing or tape, connecting the pilot chute to the deployment bag or the canopy.



C License:  The third level license issued by USPA. USPA C-license holders may apply when qualified for the USPA AFF, IAD, and Static-Line Instructor ratings, ride as passenger on USPA Tandem Instructor training and rating renewal jumps, and participate in intermediate-altitude jumps and open field and level 1 exhibition jumps.

Canopy:  The major component of the parachute system comprised of fabric membranes that connect to the parachute harness by suspension lines and provide the means for the jumper to descend safely.

Canopy Formation (CF); Canopy Relative Work; (CRW):  n. 1. The intentional maneuvering of two or more open parachute canopies in proximity to or in contact with one another during descent. 2. The FAI competition discipline involving the building of canopy formations.

CANOPY RELEASE:  A device which allows immediate separation of the parachute canopy and risers from the harness.

CANOPY WRAP:The canopy of one jumper is wrapped around another jumper.

CASCADE:  The point where two or more lines of a canopy join into one.

Cell:  n. Chordwise section of a parachute canopy between the load-bearing ribs. Sometimes, any portion of a canopy separated by vertical ribs.

Certificated:  adj. Refers to FAA-approval status of parachute components, technicians (riggers), and aircraft pilots.

Check of Threes:  Pre-jump equipment self-check performed in the aircraft:   check three-ring release system (and RSL) for correct assembly; check three points of harness attachment for snap assembly or correct routing and adjustment; check three operation handles—main activation, cutaway, reserve—in place.

Chord:  n. The longest dimension from the front to the back of a wing at any given point along the span.

Chute Assis:  n. French for “falling seated,” a freeflying orientation credited to that country. (see also SIT FLYING)

Cleared:  adj. Refers to a student who has received a signature from a USPA Instructor to advance.

Climbout:  n. The act of a jumper positioning himself or herself in or near the door or on protuberances or structures outside the aircraft to prepare for launch, usually with a group.

Closing Loop:  A lace that when threaded through eyelets in the parachute container flaps and locked with a closing pin, keeps the parachute contained until activation.

Coach:  n. A non-rated operative who provides advanced skydiving training. (see also COACH, USPA)

Coach, USPA:  n. The entry-level USPA instructional rating whose holder may teach the general (non-method-specific sections of the first-jump course) and conduct group freefall and canopy skills training and jumps with students, all under the supervision of a USPA Instructor.

Coach Jump:  n. A Coach jump is any jump where a USPA Coach jumps with any person and provides instruction and/or critique to that person.

Collapsible Pilot Chute:  A hand-deployed pilot chute that automatically collapses after deployment.

Collapsible Slider:  A slider rigged so the jumper can compress or wrap it to reduce drag (see also SLIDER).

COLLINS LANYARD:A lanyard attached to the Reserve Static Line which is designed to release the non-RSL side riser in the event the RSL side riser breaks.

Container:  The portion of the parachute system that closes around and stores the folded parachute canopy and deployment device until deployment.

Cork:  v. (jar.) During high-speed group freefall maneuvers, to lose control and decelerate rapidly.


Cross Braced:  (adj.) Refers to a canopy designed with longitudinal trussing between the vertical ribs to flatten and stiffen the wing in flight.

CROSS CONNECTORS:  Straps attached between the risers. Used for canopy formation, they should be from front to rear only to prevent the docked jumper from sliding back up the lines. Especially important for plane formations. Also used with some reserve static-line systems and attached from side to side to prevent premature reserve deployment if only one riser is released.

Crossport:  n. A vent cut into the structural rib of a parachute canopy to equalize air pressure between two cells.

Crosswind:  Perpendicular to the direction of the wind.

Cutaway (n):  Procedure where the jumper releases from the main parachute prior to activating the reserve parachute. Used in the event of a main parachute malfunction to prevent an entanglement with the deploying reserve; in the event of a canopy entanglement with another jumper; and also in case the wind causes the canopy to drag a jumper after landing.

Cutaway Handle:  Pillow or loop handle of a two-handled system, normally located on the jumpers right-side chest, used to initiate a cutaway. Sometimes referred to as a three-ring release handle.


D License:  The fourth and highest level or license issued by USPA. USPA D-license holders may participate in all competitions at the national level, apply when qualified for all USPA instructional and proficiency ratings, and participate in high-altitude jumps.

Decision Altitude:  A predetermined altitude at which you must decide and act during an emergency.

Delta:  Freefall position with legs extended and arms back to initiate a forward dive.

Demonstration JUMP (Demo):  (see EXHIBITION JUMP)

DENSITY ALTITUDE:  An expression of air density relative to standard atmospheric pressure at sea level. The pilot calculates pressure altitude and temperature and compares the result with an equivalent altitude MSL at standard temperature.

Deployment:  After activation, extraction of the parachute from the container and full extension of the system prior to inflation.

Deployment Device:  Intermediate container, usually a bag (D-bag), that contains or constricts the folded parachute through complete line deployment.

Descent rate:  The downward horizontal speed of an aircraft or parachute, usually measured in feet per minute.

Diaper:  A type of deployment device consisting of a fabric panel attached near the lower part of a canopy which prevents canopy inflation until full line stretch. Used frequently with round parachutes to reduce opening shock and malfunctions.

Direct Supervision:  1. The attentive oversight of an activity taking place in the immediate presence of the supervisor, who is personally responsible for the proper conduct of the activity. (USPA definition) 2. A certificated rigger personally observes a non-certificated person packing a main parachute to the extent necessary to ensure that it is being done properly, and takes responsibility for that packing. (FAR 105 definition) (see also Supervision)

Dive Blocks:  Hand grips (not loops) on the front risers to facilitate diving the canopy.

Dive Loops:  Handles on the front risers to facilitate diving the canopy.

Diver Exit:  Leaving an aircraft by diving out of the aircraft door; made without positioning or bracing to achieve a stable entry into the airstream.

Diving (freefall):  To rapidly descend toward and then make a controlled approach relative to a target.

Dock:  v. To make physical controlled contact with another skydiver while in freefall; or, when building canopy formations, with another jumper’s canopy.


Downwind:  1. adj. The direction toward which the air is moving. 2. adv. or adj. positioned farther along the wind’s path. 3. n. (jar.) a downwind-facing landing.

downwind leg:  The portion of the landing approach flown with the wind blowing from behind the jumper.

Drogue:  A trailing drag device used to retard the movement of an object through the air, used in skydiving to regulate the fall rate of tandem skydivers.

Droguefall:  In tandem skydiving, the portion of the descent where a drogue has been deployed between freefall and main parachute deployment.

DROP ZONE:  n. 1. Skydiving establishment or intended parachute landing area. (USPA definition) 2. Any pre-determined area upon which parachutists or objects land after making an intentional parachute jump or drop. The center-point target of a drop zone is expressed in nautical miles from the nearest VOR facility when 30 nautical miles or less; or from the nearest airport, town, or city depicted on the appropriate Coast and Geodetic Survey World Aeronautical Chart or Sectional Aeronautical Chart, when the nearest VOR facility is more than 30 nautical miles from the drop zone. (FAR 105 definition) (see also Sanctioned Drop Zone)

DUAL ASSEMBLY:  Refers to a two-canopy parachute system. Includes the main and reserve canopies, harness and container system, and all other components.


Dynamic Stall:  n. An action that occurs following the flare of a ram-air canopy, where the load (jumper) has swung forward under the canopy from the braking action and begins to swing back. (see also REVERSE FLIGHT and STALL)


Elliptical:  n., adj. (jar.) Refers to a class of canopies with a tapered or approximately elliptical planform.

EMERGENCY PARACHUTE:  A certificated parachute which is intended for emergency use; typically, the parachute a pilot wears.

End Cell:  The last chordwise section of a parachute canopy on either end.

End-Cell Closure:  Deflated end cell. Routine opening problem, usually correctable.

ENDORSEMENT:An act of giving one's public approval or support to someone or something.

EXAMINER, USPA:  The highest level of the instructional rating program. An Examiner is an experienced USPA Instructor who has met additional proficiency requirements and passed a series of written examinations on a wide variety of skydiving related subjects. An Examiner has all of the privileges of a USPA Safety & Training Advisor.

Exhibition JUMP:  An exhibition jump, also called a display or demonstration jump, is a jump at a location other than an existing drop zone done for the purpose of reward, remuneration, or promotion and principally for the benefit of spectators.

EXIT POINT:  The point on the ground over which skydivers leave the aircraft.

Exit Weight:  The combined weight of the jumper and all his or her equipment for that jump.

EXTRAORDINARY SKYDIVE:  n. Night jump, water jump, jump from above 15,000 feet MSL, exhibition jump, pre-planned cutaway jump, and other jumps requiring special equipment and procedures that might be unfamiliar to most jumpers.





Farmer McNasty:  (jar.) Unenlightened term for a disenchanted drop zone neighbor with whom communications with jumpers are strained or have broken down.

FEDERAL AVIATION ADMINISTRATION (FAA):  An agency of the U.S. Department of Transportation whose primary function and responsibility is to control the nation’s air traffic, including the certification of all civil aircraft and accessories, licensing of all civil pilots, mechanics, and riggers, and administration of the Federal Aid to Airports Program.

FEDERAL AVIATION REGULATIONS (FARs):  The parts of the Code of Federal Regulations that apply to aviation.

FEDERATION AERONAUTIQUE INTERNATIONALE (FAI):  An international organization which governs all aviation sports, certifies all official aviation and space records, and governs official international competitions. Operates through a non-profit National Aero Club in each country.

Final Approach:  The final portion of flight before a jumper or aircraft lands.

Flare:  1. v. Under canopy:   To convert the downward speed of a parachute momentarily into lift. 2. v. In freefall:   To decelerate prior to approaching a formation. 3. n. The act of flaring. 4. n. A membrane used to distribute the load of a parachute at the line attachment points of some canopies.

Flat Delta:  Freefall position with the body on one plane, legs extended and arms swept back, used as a starting or intermediate position when developing a track.

Flat Flying:  Freefall orientation primarily belly to earth.

FLAT TURN:A canopy turn performed at braked flight that conserves altitude.

Floater:  A jumper positioned outside the aircraft to leave slightly prior to the person or group designated as the target for the initial freefall formation (see also BASE). A floater maneuvers from a position below the base relative to the horizon.

FOREIGN PARACHUTIST:  A parachutist who is neither a U.S. citizen nor a resident alien and is participating in parachute operations within the United States using parachute equipment not manufactured in the United States. (FAR 105 definition)

FORMATION SKYDIVING (Relative Work):  1. Aerial maneuvers by two or more freefalling skydivers with each other, usually to form geometric formations. 2. Competition discipline of flat-flying.

FREE BAG:Intermediate container that contains or constricts the folded parachute through complete line deployment that is not attached to the deploying parachute.

Free Fly:  v. To exit unlinked with other jumpers.

FREEFALL:  The portion of a parachute jump or drop between aircraft exit and parachute deployment in which the parachute is activated manually by the parachutist at the parachutist’s discretion or automatically, or, in the case of an object, is activated automatically. (FAR 105 definition)

Freeflying:  n. 1. An unrestricted freefall discipline characterized by varied presentations to the relative wind. (see also SIT FLYING and HEAD DOWN) 2. n. The competition event of freeflying.

Freestyle:  1. A solo freefall discipline that involves choreographed multi-orientation static and dynamic maneuvers. 2. The competition event of freestyle performed as part of a team with a camera flyer (freestyle skydiving).

Full Flight:  The stabilized state of hands-off canopy flight under an open and fully functioning parachute.

Funnel:  n., v. A freefall skydiving formation which has become unstable, usually due to one or more jumpers flying out of position, causing the participants to collapse the formation and land on top of each other.


GLIDE:  n., v. The combined horizontal and vertical movement of a descending canopy.

Glide Angle:  (see GLIDE PATH)

glide path:  The trajectory of a parachute as it descends in flight towards a landing point on the ground.

Go-Around:  n. (jar.) An in-flight operation where the aircraft circles at jump altitude.

Governance Manual, USPA:  The official bound collection of the USPA Constitution and By-Laws.

Ground speed:  The speed of an airborne aircraft or parachute relative to the ground it traverses in a given period of time.

Group Member:  Skydiving centers that have pledged to follow USPA Basic Safety Requirements, including providing USPA-developed first-jump courses, using current USPA-rated instructors and providing USPA-required skydiving equipment. At USPA Group Member skydiving centers, all skydivers cleared for self-supervision must be current USPA members.


HAND-DEPLOYED PILOT CHUTE:  A small parachute thrown by hand in freefall to extract the main parachute from its container. (see also PULL OUT and THROW OUT)

Hard Deck:  A predetermined altitude above which an action must occur or below which an action must not occur. In rating courses, it indicates a minimum altitude by which a certain maneuver must be performed in order to get credit for the action.

Harness:  n. The webbing of a parachute system that surrounds and retains a jumper.

Harness and Container System:  The major component of a parachute system, usually unitized, which the jumper dons for the jump. It contains the canopies and certain accessory devices.

Harness Hold:  A skydiving training discipline where a student is trained for independent, solo freefall but is accompanied by at least one USPA AFF Instructor until meeting the requirements in the BSRs for self-supervision in freefall. On the initial jumps, the AFF Instructor(s) assist the student on exit via a harness grip.

Head Down:  adj., adv. Inverted vertical or nearly vertical freeflying orientation.

HIGH-PERFORMANCE LANDING AREA:   An area at a drop zone that DZ management has designated as separate from the normal landing area for canopy pilots to perform high-performance landings.

HOOK KNIFE:  A hook-shaped knife with an inside cutting edge. Used in certain emergencies to sever problem lines or components of a parachute system.

Hook Turn:  (jar.) A canopy maneuver that results in a steep dive.

Hooker Harness:  A single-point aircraft passenger restraint system that integrates with a parachute harness. Designed by Jack Hooker.

Horseshoe:  n. A partial parachute malfunction where part of the deployed parachute is entangled with the jumper or his or her equipment.




Initiated Deployment:  Refers to a pull sequence prompted or cued by the instructor where the student begins the sequence but may be completed by the instructor.

INSPECT AND REPACK:Rigging term used on reserve parachute packing data cards.

Instructional Rating Manual (IRM), USPA:  The manual containing the collected documents and references required to conduct any course for USPA Coach or USPA Instructor ratings.

INSTRUCTOR Rating COURSE, USPA:  A course registered with USPA Headquarters to train, qualify, and test applicants for the USPA Instructor rating.

INSTRUCTOR, USPA:  The holder of a USPA Instructor rating qualified in one or more of four methods of instruction:   USPA Accelerated Freefall, instructor-assisted deployment, static line, or tandem. The mid level of the USPA instructional rating hierarchy. A USPA Instructor may train and certify a student for the USPA A License, supervise USPA Coaches, and is eligible for appointment as USPA Safety & Training Advisor.

Instructor-Assisted Deployment (IAD):  A method of passive deployment used for training skydiving students making their initial jumps. A USPA IAD Instructor controls a hand-deployed pilot chute while a student moves into position and jumps, at which point the instructor releases the pilot chute.


JUDGE:  The official who evaluates a competitor’s performance. USPA issues judge ratings at both the Regional and National levels. The FAI issues a rating for internationally recognized judges.

JUMP ALTITUDE:  Actual altitude of an aircraft above the ground at the time a skydiver exits.


JUMP RUN:  The flight of the aircraft prior to exit, generally following a predetermined path.


JUMPMASTER:  n. 1. A skydiver, typically a senior jumper or instructional rating holder, who coordinates boarding and exit order, jump flight procedures, spotting, and emergency operations with the pilot. 2. v. To dispatch jumpers. 3. n. Prior to 2002, a USPA instructional rating for supervising student jumps.

JUMPSUIT:A garment used for protection or alter performance.



Landing pattern:  n. The deliberate flight path, usually rectangular, that a jumper uses in the final phase of descent under canopy.

License:  Certificate of proficiency recognizing that a skydiver has met a specified level of experience, skill, and knowledge. There are four classes of USPA licenses: A, B, C and D. USPA licenses are recognized internationally through the FAI.

LINE DOCK:  The docking of two canopies with the docker’s canopy above the head of the person receiving the dock.

Line Twist:  n. 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 lines and/or risers. Can be dangerous when associated with a spin.

Lineover:  n. A partial malfunction of a deployed parachute resulting in lines going over the top of the canopy. Also refers loosely to the partial inversion of a round canopy. (see also Partial Inversion)


Mae West:  n. (jar., archaic) WWII term for partial inversion. (see also PARTIAL INVERSION)

MAIN ASSISTED RESERVE DEPLOYMENT (MARD):A device which uses the drag from the cutaway main canopy to assist in extracting the reserve canopy.

MAIN PARACHUTE:  A parachute worn as the primary parachute used or intended to be used in conjunction with a reserve parachute. (FAR 105 definition)

MAINTENANCE:  Inspection, overhaul, repair, preservation, and replacement of 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. (see also Alteration)

MAJOR REPAIR:  A repair that if improperly accomplished may affect weight, structural strength, performance, flight characteristics, or other qualities which determine airworthiness.

MALFUNCTION:  The complete or partial failure of a parachute canopy to accomplish proper opening, descent, or flight characteristics.


Master Rigger:  The higher of two certification levels for FAA riggers. May perform more complex repair tasks and approved alterations. (see also SENIOR RIGGER)

Mentor (skydiving):  An experienced skydiver, usually D-licensed, who can offer advice and guidance on skydiving related matters to jumpers with less experience.

mini three-ring:  Refers to a scaled-down version of the original three-ring release system. (see also three-ring release)

MINOR ALTERATION:  An alteration other than a major alteration. (see also ALTERATION and MAJOR ALTERATION)

MINOR REPAIR:  A repair other than a major repair. (see also MAJOR REPAIR)

MSL:  Altitude measured from sea level.



NAS 804:  (National Aircraft Standard 804) defines the tests and minimum performance and safety standards which must be met for a parachute to receive approval under TSO C-23b. Adopted in 1949 and superseded in 1984 by AS 8015A.

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 formation. Designed by Nasser Basir.

NATIONAL AERONAUTIC ASSOCIATION (NAA):  The National Aero Club of the USA which represents the FAI. USPA is a division of the NAA.


NIGHT JUMP:  A skydive made from one hour after official sunset to one hour before official sunrise. The FAA considers any jump made after sunset and before sunrise a night jump requiring equipment specified in FAR 105.

NORMAL LANDING AREA:  A landing area at a drop zone that DZ management has designated as separate from the high-performance landing area.

NOTAM (Notice to Airmen):  An air traffic advisory or notice filed with an FAA Flight Service Station by an airspace user.


OBJECT:  Any item other than a person that descends to the surface from an aircraft in flight when a parachute is used or is intended to be used during all or part of the descent. (FAR 105 definition)

OPEN BODY OF WATER:  A body of water in which a skydiver could drown.

OPENING POINT:  The ground point of reference over which the skydiver opens the parachute.

Opening Shock:  (jar.) The decelerating force exerted on the load as the parachute deploys and inflates. Caused by the resistance of the canopy and items associated with it.

OSCILLATION:  1. The swinging or pendulum motion of the suspended load under a canopy. 2. In canopy formation, the swaying or swinging of a formation caused by poor docking, turbulent air, or too much movement of the people in the formation.

OUTBOARD:  Facing to the outside, such as a ripcord facing to the side of the jumper rather than toward the breast bone.



PACK:  v. To fold and close a parachute system in preparation for jumping.

PACKING DATA CARD:A card kept with a parachute system which records the maintenance on that system.

PARACHUTE:  A fabric device that slows the descent of a falling object; derived from the French words “para,” to shield, and “chute,” to fall. Thus, parachute literally means “to shield from a fall.”

PARACHUTE DROP:  The descent of an object to the surface from an aircraft in flight when a parachute is used or intended to be used during all or part of that descent. (FAR 105 definition)

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 or intended to be used during all or part of that descent. (FAR 105 definition)

Parachute Landing Fall (PLF):  n. A method developed by the U.S. military to minimize the chance of injury from a hard landing under parachute. The jumper distributes the force of the landing in an orderly manner over the most robust areas of the body.

PARACHUTE OPERATION:  The performance of all activity for the purpose of, or in support of, a parachute jump or a parachute drop. This parachute operation can involve, but is not limited to, the following persons: parachutist, parachutist in command and passenger in tandem parachute operations, drop zone or owner or operator, jump master, certificated parachute rigger, or pilot. (FAR 105 definition)

PARACHUTIST:  A person who intends to exit an aircraft while in flight using a single-harness, dual parachute system to descend to the surface. (FAR 105 definition) (see also SKYDIVER)

PARACHUTIST IN COMMAND:  The person responsible for the operation and safety of a tandem parachute operation. (FAR 105 definition) Not necessarily a USPA instructional rating holder.

Paragliding n. (also Parapente):  An activity involving the use of a ram-air inflated wing, resembling a parachute, for gliding. Flights typically initiate by foot-launching from a hill or from a ground-based tow. Because paragliding jumping does not meet the FAA’s definition of “the descent of an object to the surface from an aircraft in flight,” it is not regulated by the FAA or addressed by USPA.

PARTIAL INVERSION:  Inflation malfunction of a round canopy where one side passes through and inflates between two lines of the other side, resulting in two inflated lobes. (see also LINEOVER)

PASSENGER PARACHUTIST:  A person who boards an aircraft, acting as other than the parachutist in command of a tandem parachute operation, with the intent of exiting the aircraft while in flight using the forward harness of a dual harness tandem parachute system to descend to the surface. (FAR 105 definition) USPA further defines a passenger parachutist as either a licensed skydiver or a tandem student.

PERMEABILITY:  The amount or volume of air which can pass through a fabric assembly.

PILOT CHUTE:  A small parachute used to initiate and/or accelerate deployment of a main or reserve parachute. (FAR 105 definition)

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 separating from the system. Typically a velcro strip or break cord of known strength is used.

Pin:  1. v. To fly to another jumper and take grips on the jumper (freefall) or canopy (canopy formation). 2. n. The first jumper to make contact with the base, or target jumper, to begin a formation. 3. n. Retaining device that when passed through a closing loop, locks the parachute system closed until activation.

Pin Check:  n. (jar.) Pre-jump inspection of the parachute.


PLANE:  n. A compressed vertical canopy formation.

Planform:  The shape or footprint of a wing surface.

PLANING:  v. The act of compressing a parachute stack.

POISED EXIT:  A departure from an aircraft wherein the jumper uses an external structure as a brace to assist in gaining a stable position immediately upon leaving the aircraft.

POROSITY:  The ratio of open area to closed area in a fabric. Graded as high, low, or zero. Tightly woven and treated material has a lower porosity than loosely woven material.

PRACTICE DEPLOYMENT:  An in-air exercise used to learn how to locate and operate a parachute deployment handle prior to opening. It may consist of pulling or throwing a practice or dummy handle (instructor-assisted deployment or static-line jumps) or touching the actual deployment handle in freefall or tandem droguefall.

PREMATURE OPENING:  Unintentional opening of a parachute.

Projected Landing Point:  The expected landing spot on the ground, based on the glide path of the parachute.

Prop Blast:  1. n. The airflow created by a propeller that is developing thrust. 2. n. (jar.) relative wind on exit

Pud:  n. (jar.) An aerodynamically low-profile, soft handle that is ergonomically designed to fit into a clenched fist. Used for various parachute operation handles.

PULL OUT:  n. A type of hand-deployed parachute activation system. The jumper pulls a handle connected to the container closing pin and the internally packed pilot chute. (see also HAND DEPLOYED PILOT CHUTE)

Pull-up Cord:  A packing aid used to thread the closing loop through eyelets in the container and removed once the closing pin is inserted.


RAM-AIR PARACHUTE:  A 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. (FAR 105 definition)

RATING RENEWAL SEMINAR, USPA:  A meeting of USPA instructional rating holders to exchange information, introduce and discuss new ideas, and to develop, improve, or assure the quality of skydiving instruction.

RECOMMENDATIONS, USPA:  Principles, policies, and concepts applicable to skydiving or a related subject which are derived from experience or theory, compiled by USPA, and offered for guidance.

REGIONAL DIRECTOR, USPA:  Members of the USPA Board elected from a specified geographical area and responsible for representing the interests of the skydivers in that USPA Region.

Relative Wind:  The relative airflow opposite a body’s trajectory, irrespective of the horizon.


REMOVABLE DEPLOYMENT SYSTEM (RDS):Primarily used by high performance canopy pilots it is a system that allows the slider and in some cases the deployment bag and pilot chute to be removed after opening and helps decrease drag.

RESERVE PARACHUTE:  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. (FAR 105 definition)

Reserve Static Line (RSL):  A connection between the main risers and the reserve activation system intended to initiate reserve activation following the release of a deployed main parachute.

Reverse Flight (FULL STALL):  A non-flying canopy maneuver that collapses the canopy and may cause it to spin. Results from depressing the toggles until the trailing edge is lower than the leading edge. May result in an unrecoverable malfunction. (see also STALL and DYNAMIC STALL)

Rib:  A vertical and longitudinal fabric membrane that forms the airfoil shape and primary structure of a ram-air canopy.

Rig:  (jar.) 1. n. The complete parachute system used for skydiving. 2. v. The act of maintaining, repairing, or modifying a parachute system. 3. v. To don a parachute (Rigging Up).

Rigger:  An FAA-certificated parachute technician. (see also MASTER RIGGER and SENIOR RIGGER)

Ripcord:  An assembly, usually constructed with a metal cable that, when pulled, activates an operation on a parachute system.

RISER DOCK:  In canopy formation, a momentum dock that puts the risers into the hands of the receiver. A very advanced technique.

Riser Loops; Riser Blocks:  Gripping loops or devices on a riser that make it easier to grasp.

Riser(s):  Webbing straps that connect the main lift webs of the parachute harness to the lines of the canopy.



SAFETY & TRAINING ADVISOR (S&TA), USPA:  A local person appointed by the USPA Regional Director as his or her representative and who is available to provide advice and administrative assistance as the USPA representative at an individual drop zone or specified area.

Sanctioned Drop Zone:  A drop zone which has been verified by a USPA Safety & Training Advisor or a USPA Regional Director as complying with the minimum drop zone requirements as stated in the USPA Basic Safety Requirements section of the USPA Skydiver’s Information Manual. (see also Drop Zone)

SELF-SUPERVISION:  The point within a student’s training when he has been cleared by a USPA Instructor to jump without instructor supervision in freefall but has not yet completed all of the requirements for the USPA A license. At USPA Group Member skydiving centers, all skydivers cleared for self-supervision must be current USPA members. See Category E: Introduction of the Integrated Student Program.

Senior Rigger:  The initial certification level for FAA riggers that allows its holder to pack and maintain a parachute system and perform simple repairs. (see MASTER RIGGER)

SIM:  Abbreviation for Skydiver’s Information Manual (this book). (see SKYDIVER’S INFORMATION MANUAL)

SINGLE OPERATION SYSTEM (SOS):  Refers to a parachute harness and container operation system with a combined single-point riser release and reserve ripcord handle. Pulling one handle will both release the risers and pull the reserve. (See also TWO-HANDLED SYSTEM)

SINGLE-HARNESS, DUAL-PARACHUTE SYSTEM:  The combination of a main parachute, approved reserve parachute, and approved single-person harness and dual-parachute container. This parachute system may have an operational automatic activation device installed. (FAR 105 definition)

Sit Flying:  Upright vertical freefly orientation based on a seated position. (See also CHUTE ASSIS)

Skyboard:  (see SURFBOARD)

SKYDIVE:  1. n. The descent of a person to the surface from an aircraft in flight when he or she uses or intends to use a parachute during all or part of that descent. 2. v. To jump from an aircraft with a parachute.

SKYDIVER:  A person who engages in skydiving.

Skydiver’s Information Manual (SIM), USPA (this book):  The official bound collection of the USPA Basic Safety Requirements, USPA recommendations, relevant FAA references, and other USPA policies and programs that affect the majority of skydivers.

Skysurfer:  A skydiver who jumps with a surfboard (skyboard).

Skysurfing:  1. A freefall skydiving discipline using a specially rigged surfboard (skyboard). 2. The competition event by that name.

SLIDER:  A device which controls a canopy’s inflation by progressively sliding down the suspension lines during inflation. Found on most ram-air canopies.

Slinks:  A type of Spectra fabric connector link developed by Performance Designs, Inc., for attaching the lines of the parachute to the risers.

Solo deployment:  Refers to a pull sequence not prompted or cued by the instructor where the student starts and finishes their pull sequence without instructor contact.

Solo jump:  A jump where a skydiver is not engaged in formation skydiving.

Solo Jumper:  A skydiver who is not engaged in formation skydiving.

Solo skydiver:  See solo jumper.

Solo Student:  A skydiving student who uses a single-harness, dual-parachute system.


Span:  The dimension of a wing measured from tip to tip.

SPEED SKYDIVING:Skydiving discipline in which the goal is to achieve and maintain the highest possible speed for a predetermined amount of time.

SPOTTING:  Selecting the correct ground reference point over which to leave the aircraft, selecting the course for the aircraft to fly, and directing the pilot on jump run to that point.

STABILITY:  That property of a body which causes it, when its equilibrium is disturbed, to develop forces or movements tending to restore the original condition. In skydiving, control of body position during freefall.

STABLE FREEFALL POSITION:  A position attained by a freefalling skydiver in which only controlled, planned movements are made.

STACK:  A vertical canopy formation with the jumpers gripping the canopy or lines just below the canopy.

Stall:  n. The state of canopy flight control characterized by decreased glide and increased rate of descent. (see DYNAMIC STALL and REVERSE FLIGHT)

STATIC LINE:  A line of cable or webbing, one end of which is fastened to the parachute, the other to some part of the aircraft, used to activate and deploy or partially deploy the parachute as the load falls away from the aircraft.

STATIC-LINE JUMP:  A parachute jump during which a static line is used to deploy or partially deploy the parachute. Used for training student skydivers.

step-through:  (see THREAD-THROUGH)

STUDENT:  A skydiver trainee who has not been issued a USPA A license.

Supervision:  The general oversight of an activity taking place where the supervisor is readily available for counsel and direction and who is responsible that the activity is satisfactorily completed. (see DIRECT SUPERVISION)

Surfboard (Skyboard):  n. A rigid panel, similar to a snowboard, attached to a jumper’s feet.

SUSPENSION LINES:  Cords, attached from the bottom of the parachute canopy to the risers, that distribute and suspend the weight of a skydiver under the inflated canopy.

Swoop:  The controlled flight from above of one body to meet or fly close to another body, a stationary object, or the ground.

Swoop Pond; Swoop Ditch:  A water obstacle used as a high-performance landing area.


TANDEM JUMP or TANDEM SKYDIVE:  Any skydive made using a tandem parachute system with a tandem student or licensed skydiver attached.

Tandem Jumping:  A method of skydiving, typically used for training student skydivers where one skydiver shares a tandem parachute system with another.

TANDEM PARACHUTE OPERATION:  A parachute operation in which more than one person simultaneously uses the same tandem parachute system while descending to the surface from an aircraft in flight. (FAR 105 definition)

TANDEM PARACHUTE SYSTEM:  The combination of a main parachute, approved reserve parachute, and approved harness and dual parachute container, and a separate approved forward harness for a passenger parachutist. This parachute system must have an operational automatic activation device installed. (FAR 105 definition)

TANDEM STUDENT:  Any person making a tandem skydive who has not been issued a USPA license.

TARGET:  The landing area on a drop zone. For officially sanctioned competition, a three-centimeter disk.

TECHNICAL STANDARD ORDER (TSO):  Issued by the FAA, requires compliance with minimum performance standards and specifications for material and products. Parachute specifications are referenced in TSO-C23.

TERMINAL VELOCITY:  The equilibrium velocity that a freefalling body can attain against the resistance of the air. The greatest speed at which a body falls through the atmosphere.

Thread-Through (step-through):  (jar.) n. A leg strap configuration on a parachute harness that uses a single piece of adjustable hardware. The leg strap must be un-threaded to be disconnected, or the jumper simply steps into the connected leg straps when donning the rig. (see B-12s)

three-RING RELEASE:  A type of single point release invented by Bill Booth. The system is based on three interlocking rings on each riser held in place by a small loop that is retained by a cable. Pulling one handle releases both main risers simultaneously or nearly simultaneously.

THROW OUT:  1. n., adj. A type of hand-deployed parachute activation system. The pilot chute is folded into an external pouch, extracted and thrown. A curved closing pin or equivalent locking device on the bridle is extracted as jumper falls away from the pilot chute and bridle, allowing the container to open. (see Hand Deployed pilot chute) 2. v. (jar.) To initiate deployment.

Toggles:  n. Handles attached to the ends of the steering lines of a parachute canopy. (see also BRAKES)

Track:  1. n. A freefall position with the legs fully extended, knees locked, arms swept back, elbows locked, and torso fully extended and slightly bowed forward to achieve the maximum horizontal speed. 2. v. To move at maximum horizontal speed in freefall.

TRACKING SUIT:A 2-piece inflating suit that transforms the body into a human airfoil.

TRIM TABS:  A front riser pulley system for adjusting a canopy’s angle of incidence or flight attitude.


Turbulence:  Disturbed air that can affect canopy flight and integrity.

Two-Handled System:  Refers to a parachute harness and container operation system that uses separate handles for the canopy release and for reserve activation. (see SINGLE OPERATION SYSTEM)



UNITED STATES PARACHUTE ASSOCIATION (USPA):  A not-for-profit, voluntary membership association of skydivers whose purpose is promoting and representing skydiving. As a division of the NAA, it is the official representative of the FAI for skydiving in the U.S.

Upwind:  The direction from which the wind is blowing.


WAIVER:  n. 1. Exception to the BSRs filed by a USPA official indicated in SIM Section 2-2. 2. (jar.) A liability release.

WATER JUMP:  n. A skydive which includes intentionally landing in an open body of water.

Whuffo:  n. (jar.) Term for a non-skydiver (“Whuffo you jump out of airplanes?”) Considered insensitive.

WIND DRIFT INDICATOR (WDI):  n. A device used to determine the wind drift which a descending parachute will experience, so constructed as to descend at a rate comparable to a skydiver of average weight descending under a fully deployed main canopy of average specifications. Usually a weighted strip of crepe paper 10 inches wide and 20 feet long.

WING LOADING:  n. The jumper’s exit weight divided by the area of the parachute canopy, expressed in the United States in pounds per square foot.

Wing Suit:  n. A gliding jumpsuit designed with fabric membranes between the legs of the jumper and from each arm to the torso.


ZOO DIVE:A skydive that becomes chaotically disorganized with many jumpers out of position both vertically and horizontally.