Speed skydiving is a
skydiving
Parachuting, including also skydiving, is a method of transiting from a high point in the atmosphere to the surface of Earth with the aid of gravity, involving the control of speed during the descent using a parachute or parachutes.
For ...
competition in which the goal is to achieve and maintain the highest possible
terminal velocity
Terminal velocity is the maximum velocity (speed) attainable by an object as it falls through a fluid (air is the most common example). It occurs when the sum of the drag force (''Fd'') and the buoyancy is equal to the downward force of gravit ...
. It was developed in the late 1990s and is the fastest non-motorized sport on Earth. The speed, achieved by the human body in
free fall
In Newtonian physics, free fall is any motion of a body where gravity is the only force acting upon it. In the context of general relativity, where gravitation is reduced to a space-time curvature, a body in free fall has no force acting on i ...
, is a function of several factors; including the body's
mass
Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different elementar ...
, orientation, and skin area and texture. In stable, belly-to-earth position, terminal velocity is about 200 km/h (120 mph). Stable freefall head down position has a terminal speed of 240–290 km/h (around 150–180 mph). Further minimization of
drag by streamlining the body allows for speeds over 500 km/h (310 mph).
Competition
![Masciaoro2019](https://upload.wikimedia.org/wikipedia/commons/b/b5/Masciaoro2019.jpg)
Speed Skydiving is a competition discipline within the sport of Skydiving. The competition objective is for the competitors to fly their body as fast as possible to achieve the highest average vertical speed through a 3 second window.
The speed is measured using a Speed Measuring Device (SMD) worn on the competitor’s helmet. The current technology used to measure the speed is GPS technology using the FlySight device (https://www.flysight.ca/). Previously (see below) barometric measuring devices were used.
The competitors exit from the competition aircraft between 13,000ft and 14,000ft (3,962m to 4,267m). Each competitor then turns 90° from the direction in which the aircraft is travelling, alternately left and right. The competitors then accelerate by flying head-first towards the earth, only slowing down once they have passed the 7,400ft competition window from their exit altitude. The score is the average vertical speed in km/h of the fastest 3 second which the competitor achieves within the competition window.
Speeding Skydiving is now one of the disciplines governed by the International Skydiving Commission (https://fai.org/commission/isc), a commission of the FAI (https://fai.org/). Before being adopted by the ISC, Speed Skydiving was governed by International Speed Skydiving Association (https://www.speed-skydiving.com/), who developed initial rules and continues to conduct competitions. The ISSA maintains eternal ranking lists for the current GPS measured events (https://www.speed-skydiving.com/index.php/rankings/eternal-ranking-gps) and one performances measured using barometric SMDs (https://www.speed-skydiving.com/index.php/rankings/eternal-ranking-barometric).
Records
The current world record for the fastest competitor using the GPS measuring system is Marco Hepp from Germany. He flew 529.77 km/h in the competition window at th
4th FAI World Speed Skydiving Championshipsin October 2022. The fastest female competitor is Natisha Dingle of Australia who flew 477.88 km/h in the competition window at the same competition.
History
The first competition organized in the USA in Deland Florida was in 1998 with the barometric Protrack built by Larsen & Brusgaard (https://www.lbaltimeters.com/). The first speed skydiving competition in Europe was organized in September 1999 at the drop zone Gap-Tallard (France) and was won by Mike Brooke. The first international world cup was organized in 2000 by the ISST (International Speed Skydiving Tribe) lead by Mike Brooke who pushed the sport forwards with use of two measuring devices. The devices were set on each side of the parachute of each participant instead of the foot to take away effects of dynamic air pressure on the results. An International speed skydiving world cup was run in Deland (Florida), Lincolnshire, UK, Botten, Switzerland, Lapalisse (France), Empuriabrava (Spain), Texel (Holland).
Terminal Velocity
The terminal velocity of a falling body occurs during free fall when the force due to gravity is exactly balanced by the force due to
air resistance
In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding flu ...
, such that the body experiences zero acceleration. The formula for terminal velocity (where
buoyancy
Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the p ...
in air is negligible) is given by the thrust
:
![Marco Hepp](https://upload.wikimedia.org/wikipedia/commons/4/4d/Marco_Hepp.jpg)
where
* is the
mass
Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different elementar ...
of the falling object
* is the
acceleration due to gravity (9.8 m/s
2)
* is the
drag coefficient
In fluid dynamics, the drag coefficient (commonly denoted as: c_\mathrm, c_x or c_) is a dimensionless quantity that is used to quantify the drag or resistance of an object in a fluid environment, such as air or water. It is used in the drag equ ...
(~0.7 for head down position, ~1 for belly-to-earth position)
* is the
density
Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematical ...
of the fluid through which the object is falling (1.23 kg/m
3 for air at sea level, and ~0.99 kg/m
3 at the middle of the measurement zone (2200m))
* is the
projected area
Projected area is the two
dimensional area measurement of a three-dimensional object by projecting its shape on to an arbitrary plane. This is often used in mechanical engineering and architectural engineering related fields, specifically hardne ...
of the object, or area cross-section (~0.18 m
2 for head down position, ~0.7 for belly-to-earth position)
So, for a human in belly-to-earth position ( m
2, kg, ) this gives 50.6 m/s, about the terminal velocity of the typical skydiver of 55 m/s.
The skydiver cannot increase their mass easily enough to significantly increase terminal velocity, and the skydiver's area cross-section is limited by their helmet and shoulders in a head-down dive position. The most significant difference comes from the skydiver reducing their coefficient of friction. The head-down body position has to be carefully managed to be as streamlined as possible, while special helmets and slick body suits reduce
skin friction
Skin friction drag is a type of aerodynamic or hydrodynamic drag, which is resistant force exerted on an object moving in a fluid. Skin friction drag is caused by the viscosity of fluids and is developed from laminar drag to turbulent drag as a f ...
, which is a function of surface area and texture. The shape and rigidity of the suits also have to be designed to minimize the
coefficient of drag
In fluid dynamics, the drag coefficient (commonly denoted as: c_\mathrm, c_x or c_) is a dimensionless quantity that is used to quantify the drag or resistance of an object in a fluid environment, such as air or water. It is used in the drag equ ...
.
[ Finally, a skydiver must reach their maximum speed at as high an altitude as possible so that the density of air is at a minimum.
]
Weather
Weather can have an extraordinary effect on a competition as well as individual divers. In the event of bad weather or air traffic circumstances, the exit altitude is lowered. In addition, thick cloud conditions may cause a delay in the jump time altogether.
See also
* Red Bull Stratos
Red Bull Stratos was a high altitude skydiving project involving Austrian skydiver Felix Baumgartner. On 14 October 2012, Baumgartner flew approximately into the stratosphere over New Mexico, United States, in a Gas balloon, helium balloon befor ...
Notes
{{DEFAULTSORT:Speed Skydiving
Parachuting