Wingsuit flying

Wingsuit flying (or wingsuiting) is the sport of flying through the air using a wingsuit, which adds surface area to the human body to enable a significant increase in lift. The modern wingsuit, first developed in the late 1990s, creates a surface area with fabric between the legs and under the arms. Wingsuits are sometimes referred to as "birdman suits" (after the makers of the first commercially available wingsuit), "flying squirrel suits" (due to their resemblance to the animal), and "bat suits" (due to their vague resemblance to the animal or perhaps the superhero).

A wingsuit flight normally ends by deploying a parachute, and so a wingsuit can be safely flown from any point that provides sufficient altitude for flight and parachute deploymentnormally a skydiving drop aircraft, or BASE-jump exit point. The wingsuit flier wears parachute equipment specially designed for skydiving or BASE jumping. While the parachute flight is normal, the canopy pilot typically unzips arm wings (after deployment) to be able to reach the steering parachute toggles and control the descent path.

History

An early attempt at wingsuit flying was made on 4 February 1912 by a 33-year-old tailor, Franz Reichelt, who jumped from the Eiffel Tower to test his invention of a combination of parachute and wing, which was similar to modern wingsuits. He misled the guards by saying that the experiment was going to be conducted with a dummy. He hesitated quite a long time before he jumped, and hit the ground head first, opening a measurable hole in the frozen ground, but an autopsy showed that he died of a heart attack before hitting the pavement. A film of his attempt exists.

A wingsuit was first used in 1930 by a 19-year-old American, Rex Finney, of Los Angeles, California, as an attempt to increase horizontal movement and maneuverability during a parachute jump. These early wingsuits were made of materials such as canvas, wood, silk, steel, and whalebone. They were not very reliable, although some "birdmen", notably Clem Sohn and Leo Valentin, claimed to have glided for miles.

In the mid-1990s, the modern wingsuit was developed by Patrick de Gayardon of France, adapted from the model used by John Carta. In 1997, the Bulgarian Sammy Popov designed and built a wingsuit which had a larger wing between the legs and longer wings on the arms. His prototype was developed at Boulder City, Nevada. Testing was conducted in a vertical wind tunnel in Las Vegas at Flyaway Las Vegas. Popov's wingsuit first flew in October 1998 over Jean, Nevada, but it never went into commercial production. Popov's design was a great improvement in creating lift; it was able to slow the vertical speed to 30 km/h while gliding horizontally at speeds over 300 km/h. In 1998, Chuck "Da Kine" Raggs built a version which incorporated hard ribs inside the wing airfoils. Although these more rigid wings were better able to keep their shape in flight, this made the wingsuit heavier and more difficult to fly. Raggs' design also never went into commercial production. Flying together for the first time, Popov and Raggs showcased their designs side-by-side at the World Free-fall Convention at Quincy, Illinois, in August 1999. Both designs performed well. At the same event, multiple-formation wingsuit skydives were made which included de Gayardon's, Popov's, and Raggs' suits.

Commercial era

In 1999, Jari Kuosma of Finland and Robert Pečnik of Slovenia teamed up to create a wingsuit that was safe and accessible to all skydivers. Kuosma established Bird-Man International Ltd. the same year. BirdMan's "Classic", designed by Pečnik, was the first wingsuit offered to the general skydiving public. BirdMan was the first manufacturer to advocate the safe use of wingsuits by creating an instructor program. Created by Kuosma, the instructor program's aim was to remove the stigma that wingsuits were dangerous and to provide wingsuit beginners (generally, skydivers with a minimum of 200 jumps) with a way to safely enjoy what was once considered the most dangerous feat in the skydiving world. With the help of Birdman instructors Scott Campos, Chuck Blue and Kim Griffin, a standardized program of instruction was developed that prepared instructors. Phoenix-Fly, Fly Your Body, and Nitro Rigging have also instituted an instructor training program.

Despite the training and regulation, wingsuit BASE jumping remains a precarious pastime. A 2012 University of Colorado study found that for Wingsuit BASE jumping (WiSBASE) there were approximately 2 severe injuries per 1000 jumps, or with jumpers having an average of 1 severe injury for every 500 jumps they undertake.

Technical mechanics

Wingsuits in flight

The wingsuit flier enters free fall wearing both a wingsuit and parachute equipment. Exiting an aircraft in a wingsuit requires skilled techniques that differ depending on the location and size of the aircraft door. These techniques include the orientation relative to the aircraft and the airflow while exiting, and the way in which the flier spreads his legs and arms at the proper time so as not to hit the aircraft or become unstable. The wingsuit immediately starts to fly upon exiting the aircraft in the relative wind generated by the forward speed of the aircraft. Exiting from a BASE jumping site, such as a cliff, or exiting from a helicopter, a paraglider, or a hot air balloon, is fundamentally different from exiting a moving aircraft, as the initial airspeed upon exit is absent. In these situations, a vertical drop using the forces of gravity to accelerate is required to generate the airspeed that the wingsuit then converts to lift.

At a planned altitude above the ground in which a skydiver or BASE jumper typically deploys the parachute, wingsuit fliers will also deploy their parachutes. The parachute is flown to a controlled landing at the desired landing spot using typical skydiving or BASE jumping techniques.

A wingsuit modifies the body area exposed to wind to increase the desired amount of lift with respect to drag generated by the body. An attainable glide ratio of some wingsuits is 2.5:1 or more[citation needed]. This means that for every meter dropped, two and a half meters are gained moving forward. This ratio can be referred to as flight efficiency. With body shape manipulation and by choosing the design characteristics of the wingsuit, fliers can alter both their forward speed and fall rate. The pilot manipulates these flight characteristics by changing the shape of the torso, de-arching and rolling the shoulders and moving hips and knees, and by changing the angle of attack in which the wingsuit flies in the relative wind, and by the amount of tension applied to the fabric wings of the suit. The absence of a vertical stabilizing surface results in little damping around the yaw axis, so poor flying technique can result in a spin that requires active effort on the part of the skydiver to stop.

A wingsuit flyer over Palm Islands, Dubai

Wingsuit fliers can measure their performance relative to their goals with the use of free fall computers that record the amount of time they were in flight, the altitude they deployed their parachute, and the altitude they entered free fall. The fall rate speed can be calculated from this data and compared to previous flights. GPS receivers can also be used to plot and record the flight path of the suit, and when analyzed, can indicate the amount of distance flown during the flight. BASE jumpers can use landmarks on exit points, along with recorded video of their flight by ground crews, to determine their performance relative to previous flights and the flights of other BASE jumpers at the same site.

A typical skydiver's terminal velocity in belly to earth orientation ranges from 180–225 km/h (110 to 140 mph). A wingsuit can reduce these speeds dramatically. A vertical instantaneous velocity of 40 km/h (25 mph) has been recorded[citation needed]. However the speed at which the body advances forward through the air is still much higher.

The tri-wing wingsuit has three individual ram-air wings attached under the arms and between the legs. The mono-wing wingsuit design incorporates the whole suit into one large wing.