AAD - (Automatic Activation
mechanical or electronic device which
Accuracy - Also known as Precision Landing, this is a competition discipline in which the skydiver attempts to land on an established target. At the National level the target is 3 cm in diameter, about the size of a quarter. Accuracy landings of various difficulty, from 20 meters to 2 meters, are required for USPA licenses.
AFF - ( Accelerated Freefall
Course). The most advanced method of learning to
AFF CC - (Accelerated Freefall Jumpmaster Certification Course). This is the
AGL - (Above Ground Level). Altitudes are in reference either to Ground Level of Sea Level (see MSL). Skydivers always use AGL when referring to altitude.
Airspeed - The speed of a flying object through the air, commonly used in reference to aircraft or canopies.
A device indicating altitude. Looks like a clock face with a single hand. It shows your height
above the ground, in thousand foot increments. Audible altimeters beep when
you fall through a preset altitude. These are only a backup for a visual
Angle of attack
- The angle at which the wing is presented to the apparent wind. With square parachutes this changes when the brakes are applied.
Backslide - To move backward in freefall relative to a neutral reference. Usually unintentional and undesirable, caused by poor body position.
Bag - The deployment bag in which the canopy is packed.
BIC - (Basic instructors course) Attended in an effort to gain a sufficient
BOC - Bottom of container, a deployment system. Refers to the location of the pilot chute. An increasingly common position for main deployment devices, as opposed to belly or leg mounted.
Body position - Ones freefall body posture. Variations in body position are what make a wide range of freefall maneuvers possible.
Boogie - A gathering of skydivers for a single purpose (skydiving). This events are usually focused on fun rather than competition. Big drop zones host several boogies a year, often on long holiday weekends.
Bounce - To land after freefall without the aid of a parachute. To land at an unsurvivable speed. Also known as " to frap", or "to go in".
Box man - The classic skydive/freefall "belly down" position. It is 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 brake lines of the canopy are synonymous with steering lines. Used together, they slow the parachute. Used independently they result in a turn.
Burble - Area of low air pressure above a descending skydiver caused by a person in freefall or a canopy in flight.. Going into someone else's burble usually results in a frommel.
Call - The time remaining until you are to board the aircraft. For example, a fifteen minute call means you will board in fifteen minutes.
Canopy - Skydiver talk for a 'Parachute'. See Main Parachute, Reserve
Cascade - The point where two lines join together so they run smoothly into one. Cascading the suspension lines results in reduced bulk and drag.
Center point - The point around which 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 point that the formation centers around.
Chute assis - French for sit flying, or freefalling with one's seat presented to the relative wind.
Container - The part of a Rig which contains the Main and Reserve Parachutes.
Crabbing - A canopy is crabbing when it is flown at an angle sideways to the ambient wind, resulting in a path across the ground that is sideways as well as forwards.
Current - To "be current" is to have jumped recently enough to retain proficiency in the sport. Uncurrent skydivers, depending on their experience, must be supervised to some degree when they resume jumping. See the
DC-3 - A type of aircraft, the Douglas DC-3 is a large, twin engined airplane capable of carrying over 40 jumpers. Like the Twin Beech, DC-3s are being rapidly replaced by more modern turbine engined aircraft.
Delta - A body position which forms
somewhat of an arrow shape.
Elliptical Parachute - A wing 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 configuration is typical of many high performance canopies. These Canopies are far more radical than Square parachutes capable of doing 360 degree turns in 1-2 seconds, with the Skydiver and Parachute parallel to the ground. There are variations between Square and Elliptical, some called Semi-Elliptical.
- The cell furthest out on a canopy.
F-111 - A fabric common in mid range canopies, F-111 is slightly permeable to air and wears faster than zero-p fabric. Pronounced "F one eleven".
FAA - ( Federal Aviation
Administration) The agency of the US government that regulates aviation activity, including skydiving.
FARs - Federal Aviation Regulations, the laws governing aviation.
Fall Rate - The rate at which you fall, another name for terminal velocity
Flare - The act of pulling down the brakes of the canopy in order to slow it down, resulting in an increased angle of attack and reduced descent rate.
FS - (Formation Skydiving) Skydiving discipline in which two or more skydivers join together in different positions to make different formations. (Previously known as relative work).
Freestyle - A type of skydiving characterized by acrobatic individual flying, reminiscent of gymnastics. (Formation skydiving stalwarts reckon this is just because they can't get stable.)
Frommel - What happens when a skydive formation self destructs.
Funnel - A funnel occurs when one or more skydivers find themselves in an unstable body position and end up in a skydivers burble. The resulting loss of stability for the other skydivers usually causes the formation to break up.
Glide ratio - The distance a canopy flies forward compared to down. A canopy with a 3:1 glide ratio flies three feet forward for every foot of vertical descent.
Grips - (or grippers) Using the hands to hold onto another skydiver in freefall or during the aircraft exits. In formation skydiving, the formations are scored as complete when every skydiver has taken the correct grips. Can also refer to the sausage shaped devices or material attached to the arms and legs of a jumpsuit for skydivers to hold on to in formations.
Ground speed. The speed of an airplane or skydiver over the ground, as opposed to through the air.
Hacky - Game in which a group of skydivers attempt to keep a small hacksack (beanbag) in the air for as long as possible by kicking it. Breaking any of the myriad of obscure but sacred hacking rules results in the offending skydiver having his bum kicked by the rest of the hackers. Also known as "A game played with a ball that doesn't bounce by people who might".
Hand deploy - To activate the parachute by manually deploying the pilot chute as opposed to pulling a ripcord.
Harness - The part of a Rig which consists of webbing and metal hardware which
Heading - The direction an aircraft, skydiver, or parachute is facing. The ability to recognize and maintain heading is crucial to jumping with others successfully. "On" or "off" heading are terms commonly used to describe exits and deployments.
Hook turn - A sudden turn close to the ground (90 degrees or more) used to build up speed for a spectacular turf surf and gentle landing. When misjudged can result in smashed bones and a lengthy stay in the hospital.
Hot fuel - When the airplane does not shut down during fueling. Do not board the aircraft while fueling is in progress.
ICC : (Instructor Certification
Course) The course one must attend and
In date - A reserve packed within the previous 120 days is said to be "in date". If more than 120 days have elapsed since the reserve was packed it is"out of date" and illegal to use.
Instructor - Someone who has held a USPA jumpmaster rating for at least one year and passed an Instructor Certification Course.
Jump run - The flight path taken by the jump plane to put the skydivers in position over the airport.
- A cover all type garment designed for specific skydiving applications such as FS, freestyle or accuracy.
Key - A signal to move on to the next step in a skydive.
King Air - A turbine aircraft made by Beechcraft and common in medium sized drop zones.
Line of flight. An imaginary line corresponding to the jump plane's path over the ground, the line of flight is a useful reference line on larger formation skydives. Also, during the jump run the skydivers will be distributed along this line of flight.
- Like pilots or sailors, skydivers log their activity and achievements in order to document their experience.
MSL - (Mean sea level). Used by pilots when defining altitude, MSL refers to feet above sea level as opposed to above the ground. Pilots always use MSL when referring to altitude.
Main Parachute - The parachute you use first. If it doesn't work you use your
- 1) The list of skydivers on the jump plane. 2) The act of going to the office where this list is maintained to put yourself on a plane. 3) The location where manifesting takes place.
Organizer - Someone with leadership skills and skydiving expertise who plans formation skydives or event functions.
- The DeHavilland Twin Otter, a very popular turbine jump ship carrying up to 23 jumpers.
Packing data card - See data card.
Parachutist - A person who uses a parachute. A Parachutist is not necessarily
- Pea gravel, used in the landing area as a target reference and because it is forgiving of hard landings.
Pilot Chute - Small parachute attached to the main parachute that is used to remove the main from the harness and fill it with air.
- 1) The skydiver who first gets to the base. Base/pin are the two people around which many formations are built. 2) The act of docking on the base. 3) The closing pin of the main or reserve container, which should both be checked prior to jumping.
- (Parachute landing fall). A technique used to minimize injury during rough landings, a PLF distributes the landing shock along feet, calves, thighs, hip and shoulder.
RSL - Reserve Static Line, a backup device for automatically deploying the reserve if the skydiver cuts away their main canopy. Note: this system is only effective in malfunctions where the main is at least partially deployed.
RW - (Relative Work)
Now known as Formation Skydiving. Skydivers in
Ram air - A modern "square" parachute, these inflate with air and take on a aerodynamic profile, much like an aircraft's wing, allowing them to be flown rather than just descending like an old style round parachute.
Relative wind - The apparent wind felt by a jumper in freefall, relative wind is the result of the skydiver's speed through the air.
Reserve Parachute - The parachute you use if your
main parachute mals. Reserve
- Someone with a certificate from the FAA stating they have successfully met the requirements to be a parachute rigger.
Rip Cord - The small handle used to deploy a spring loaded pilot chute on a freefall rig. Many expert rigs use a throwout or pull out pilot chute instead.
Risers - The webbing that connects the harness to the suspension lines. At the bottom of the risers will be a mechanism for attaching and releasing the risers and harness, usually in the form of a three ring release. On the rear risers are the brakes/steering lines. The suspension lines attach to the top of the risers with connector links, also known as rapid links.
Round - 1) A formation where each skydiver has grips on the arms of those next to him, also known as a star. 2) Shorthand for "Round Parachute".
Round Parachute - A round parachute. These range from non-steerable to a bit steer able and the user is mainly at the mercy of the wind. Cannot really be flared and give fairly hard landings. Works by providing drag to slow the descent of the Skydiver.
Running - When a canopy is flying with the ambient wind it is said to be running. This produces the greatest possible ground speed.
S&TA - Safety and Training Advisor. The S&TA is a volunteer representative of USPA who attempts to disseminate information about safety and act as a liaison between the DZ and USPA. Most S&TAs hold instructor ratings.
Sky Shark - An unwanted airplane in a drop zone area.
SOS - (Single Operation System). This system simplifies emergency procedures by combining the functions of the cut away and reserve handles in a single handle.
Square Parachute - An airfoil shaped ram-air parachute which is actually rectangular with aspect ratio's from less that 2 up to more than 3.5. The parachute is termed a 'semi rigid wing'. It is held in a wing shape by the air rushing in the front, keeping it pressurized. Squares work not by providing drag to slow the descent but by providing lift as they fly at about a 3:1 glide angle. They therefore must fly quite fast! Speeds up to 40-50mph in a straight line depending on the Canopy and the weight of the Skydiver are possible! They can be flown into the ground at in excess of 80 mph if one wants to. The most common configurations are 7 and 9 Cells and they can be made of porous material or non-porous Zero Porosity material.
Stabilizer. The vertical strips of cloth depending from the end cells of the canopy. Stabilizers improve the canopy's ability to fly straight ahead and enhance efficiency by reducing tip vortices.
Static Line - A line attaching the parachute to the plane, used to automatically deploy the parachute as soon as the parachutist exits the plane. Used to train students.
Steering lines -
The lines that run from the steering toggles on the rear risers to the trailing edge of the parachute.
TSO - (Technical Standard Order) A technical standard that all American parachutes must meet before they can be marketed. Unless specifically exempted by the FAA, a parachute must have a TSO placard to be legal.
Tandem Skydiving - A common
first jump method. In some training methods, also used until the
Assisted Freefall phase. The passenger and Instructor are harnessed together and use a the same main
parachute, the student may participate very little in the actual jump
Three ring - A parachute release mechanism that utilizes three rings of separate size in a mechanical advantage system. Invented by Bill Booth in the late 70s, the three ring release is almost universally considered the best cut away system available.
Throw Out - A type of pilot chute that the skydiver actually throws into the air rather than an old style spring loaded pilot chute.
Toggles - Handles on the steering lines.
Track - To track is to assume a body position which gives a very high horizontal speed.
Turf Surf - A long, flat skim across the grass and gentle landing that follows a properly timed and executed high performance landing (see hookturn) . When mistimed the result is a turf eat.
Turn around load - When the aircraft does not shut down between loads, but lands and picks up skydivers for immediate departure.
USPA - United States Parachute Association
Uppers - The upper winds, or winds at exit altitude. The "uppers" are often much stronger and occasionally from a different direction than ground winds.
Wave off - Prior to deployment a skydiver should make a clearly defined arm motion to indicate to others nearby that he is about to open his parachute. A good wave off is essential to the avoidance of deployment collisions.
- (Wind drift indicator). A paper streamer thrown from the jump plane to estimate winds under canopy and determine the spot.
Whuffo - Derogatory term for a non-jumper, comes from the typical non-jumper question "What for you want to jump out of a perfectly good airplane?" to which of course the answer is "because the door was open".
- An imaginary line from the desired landing area, extending directly along the direction the wind is blowing.
ZP/Zero-P - (Zero Porosity)
Non-porous to air. (Not technically the