If you've ever dreamt of soaring through the air like a superhero, you're not alone. Dreams of flying have captivated human imagination since prehistoric times. Even with the advent of aircraft and the increasing availability of air travel, the ancient question stays with us: What if we could simply spread our arms and fly like a bird?
For centuries, early flight pioneers tried to achieve this very feat by attaching artificial wings to their arms and backs. But just as the myth of Icarus ended with the Greek hero falling to his death, history books are filled with tales of enthusiastic pioneers leaping from high places, wings spread -- and plummeting back to the Earth.
Today, the dream is a reality. Resembling something between a flying squirrel and a snow angel, the wingsuit allows skydivers and BASE jumpers to leap out into the void, spread their arms and soar through the air.
In a sense, wingsuit flying is a cross between skydiving and hang gliding. Like both of these activities, wingsuit flying requires the flyer to either jump out of an aircraft or off a precipice to achieve a high enough altitude. While hang gliders can coast in for a safe landing, wingsuit flyers have to deploy their parachutes and float the rest of the way to the ground -- they simply can't reduce their speed fast enough for a safe landing without the use of a chute.
But, until the moment they pull their parachute chord, wingsuit flyers can soar horizontally at high speeds and perform aerial acrobatics -- all while descending at a rate much slower than that of a typical skydiver.
So, why is this flying and not just falling in a wacky costume? Read on to discover how physics, design and decades of experimentation have allowed wingsuit flyers to own the skies.
To understand wingsuit aerodynamics and how the outfit allows its wearer to really fly, you have to understand the basic physics of flight. The first principle to keep in mind is that air is a fluid -- much like water. Try to move your hand, palm flat, through a tub of water or stick your hand out of a moving vehicle. That force resistance you feel is the motion of the fluid (the air or the water) opposing the motion of an object (your hand).
Flight is a careful relationship of four opposing forces. Weight pulls the flying object down. Lift ensues when the downward momentum of the object meets the resistance of the air. If you have a flat surface or airfoil, then the net lift can not only slow the rate of decent, but actually move the object upward through the air.
While lift and weight cover vertical movement in the air, thrust and drag cover horizontal movement. Thrust occurs when flapping wings or an engine push an object forward. Drag, like lift, is the force exerted by the fluid against a horizontally moving object. For more information on the physics of flight, read How Airplanes Work.
A skydiver exiting an aircraft will instantly experience the pull of gravity -- the force of weight. If he or she is wearing a wingsuit, then the suit's airfoil will provide lift. However, the airfoil isn't large enough to accumulate enough lift to push the flyer's weight upward through the air. This is also why wingsuit flyers must use parachutes to land. The small wings simply can't provide enough lift to slow down flyers to a safe landing speed.
Likewise, a wingsuit provides no thrust, and rapidly flapping your arms will only send you into a steep dive or deadly spin. To soar forward through the air, a wingsuit flyer must depend on his or her glide ratio -- the relationship between lift, drag and weight that determines how far a gliding object can travel from a particular altitude. As weight pulls the flyer down, lift allows the flyer to cut horizontally through the air.
How does a wingsuit allow the wearer to achieve the required lift? Read the next page to learn the different parts of a typical wingsuit.
There are several different wingsuit designs on the market, but they generally follow the same basic design. Wingsuits are constructed from highly durable fabrics with few rigid parts, as the human body provides the framework for the membranous wing surfaces. The suit essentially transforms the human form into a full-body wing, which means the suit has to feature as much horizontal surface as possible to become an effective airfoil.
The typical wingsuit design accomplishes this with webbed wing surfaces between the legs and under the arms. The force of the opposing air inflates these membranes by pushing air through inlets in the suit, helping to keep the airfoil semirigid through flight. This means that the flyer doesn't have to maintain the shape of the wings through sheer physical force alone, but also doesn't suffer limited mobility due to a rigid wing structure. The suit straps securely to the flyer's body, without obstructing the pilot chute or the emergency handles on the chest that deploy the reserve chute.
Once a wingsuit flyer has exited the aircraft and begins falling, his first step is to spread his arms and legs in order to fully open the suit's wings. The flyer then straightens his spine, pushes his shoulders forward and straightens both legs. Since his entire body serves as an airfoil, the flyer maneuvers in the air by moving different parts of his body.
To cover the greatest distance, a flyer needs to roll his shoulders forward and bend his chin against his neck in order to push the wingsuit into a head-low position. The flyer must also keep the wings open, but not fully stretched out. Remember, the more lift, the slower the descent -- and a gliding object must sacrifice altitude and turn it into speed to cover greater distances.
To achieve the longest flying time possible, a wingsuit flyer must raise his head and look forward, while also bending at the hips, stretching the wings and pushing down against the wind. In this, the flyer achieves as much surface area as possible and creates more lift. This slows both the rate of descent and forward momentum.
When it comes to turning, a flyer simply twists his or her legs, hips, shoulders and feet to alter the shape of the airfoil -- any part of the wingsuit can influence a turn. The key is to make small movements, as large movements can force the flyer into a dive or spin. It's much like swimming underwater and moving one's body to change direction, except that each movement with a wingsuit can produce radical changes in direction.
So where did all this wingsuit technology come from? Far from a new invention, skydivers have been experimenting with wings for decades. Learn all about the history of wingsuits on the next page.
Birdmen Through the Years
The first parachute jump from an airplane in 1912 followed the Wright brothers' first successful flight by only nine years. Early skydivers were true pioneers, expanding the understanding of freefall aerodynamics with each jump. At the time, they were unable to control direction in freefall -- a skydiving technique known as tracking. They just plummeted until they activated their parachutes.
In the 1930s, test jumpers tried a number of different wing arrangements to provide better tracking -- including wood, canvas and even steel constructions. While these early "birdmen" experienced varying degrees of maneuverability, the clumsy wings often interfered with their ability to properly exit the aircraft or activate their parachutes, resulting in many casualties. Of the 75 original pioneers, 72 birdmen were killed testing new designs and techniques between 1930 and 1961 [source: Hansen]. In response to this high fatality rate, the United States Parachute Association (UAPA) banned the use of wings in skydiving.
During the 1980s, German skydiver Christoph Aarns made progress in wingsuit technology by augmenting his skydiving suit with webbed wing surfaces. While this didn't allow any increased tracking speeds, it did slow his rate of descent and provide stability. In the wake of these advancements, the UAPA lifted its ban on winged skydiving in 1987.
In the mid 1990s, French skydiver Patrick De Gayardon took this concept further, spreading wing surfaces between his legs and under each arm. De Gayardon died while testing this concept, but his three-wing design went on to become the basis for modern wingsuit designs.
The first commercially available wingsuits hit the market in 1998 and the sport has continued to grow in the decades that follow, with two wingsuit manufacturers currently offering a wide range of designs. Wingsuit flying is an extreme sport and one that draws its participants from the ranks of experienced skydivers and BASE jumpers. For this reason, it will likely remain the pursuit of established skydivers and the most adventurous daredevils. But man's desire to fly like a bird isn't fading any time soon, and each year wingsuit flyers can continue to chase world records and push the boundaries of what these suits make possible.