Wingsuit flying (or wingsuiting) is the sport of gliding 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 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 deployment—normally 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.
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 was killed when he hit the ground head first, opening a measurable hole in the frozen ground.
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.