Wingsuit Flying - Non-technical Mechanics

Non-technical Mechanics

The wingsuit flier enters freefall 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 will spread his legs and arms at the proper time so as not to hit the aircraft or become unstable in the relative wind. The wingsuit will immediately start 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 wind speed 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 can then convert to lift.

At a planned altitude above the ground in which a skydiver or BASE jumper would typically deploy his parachute, a wingsuit flier will deploy his parachute. The parachute will be 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. The glide ratio of most wingsuits is 2.5. This means that for every meter dropped, two and a half meters are gained moving forward. The ratio is also called efficiency. With body shape manipulation and by choosing the design characteristics of the wingsuit, a flier can alter both his forward speed and fall rate. The pilot manipulates these flight characteristics by changing the shape of his torso, arching or bending at the shoulders, 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.

Wingsuit fliers can measure their performance relative to their goals with the use of freefall computers that will indicate the amount of time they were in flight, the altitude they deployed their parachute, and the altitude they entered freefall. 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 110 to 140 mph (180–225 km/h). A wingsuit can reduce these speeds dramatically. A vertical instantaneous velocity of −25 mph (−40 km/h) has been recorded. However the speed at which the body advances 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.