A wingsuit may be defined as a wearable suit constructed from a suitable fabric that is flexible, intimately connected to the body, and designed to maximise either the wearer's freefall time or glide ratio. They offer humans the unprecedented opportunity to experience flight in much the same way a bird must do.
A good wingsuit flyer wearing a modern wingsuit can achieve a steady state glide ratio of around 2.5:1. But are they really flying, or just "falling sideways", as some unfamiliar with them have suggested?
Rephrasing the question into a more technical one - are the equations that describe aircraft and bird flight also applicable to wingsuits?
To answer this, we observed that verifying the standard flight equations would require, as a bare minimum, accurate velocity, acceleration, air density, and angle of attack data. Position and angular velocity data would also be useful. In order to be feasible, any instrumentation and supporting electronics to measure these variables would need to be small, lightweight, consume minimal power, and be able to be worn comfortably beneath the wingsuit without compromising the flyer's safety or flight performance.
The MTi series met our requirements perfectly. Its small size and low weight meant it was easy to secure to the flyer's chest, and its GPS antenna to the back of the helmet for optimal satellite reception.
The flight data were streamed over a serial link to a small flight data recorder we constructed. This "black box" also contained the battery to power the MTi and recording electronics.
One of the jumps performed whilst wearing this system was from the North Face of the Eiger. This spectacular location is one of the holiest sites in BASE jumping, but was also of interest for scientific reasons because of the low air density at such high altitudes. Air density is of course a function of temperature and pressure, with the latter in our case being the more important variable. The MTi has a barometer which it uses primarily to increase the accuracy of its altitude estimates, but it is also able to record the pressure data itself, which allowed for accurate estimates of air density during the flight to be made.
So after analysing flight data from dozens of jumps, what is our conclusion? Are wingsuits really flying? Yes, they most certainly are! One example of how well they adhere to the same laws of flight that aircraft do, is the linear relationship displayed by this angle of attack versus lift coefficient data.
Now that we have a working mathematical model of how wingsuits fly, we are in a position to help Visa Parviainen optimise his jet-powered wingsuit design. Part of this is expected to involve the development of a fly-by-wire system using the MTi and servo actuated thrust vectoring to help stabilise flight.
A new era of human flight is being explored!
Visa flies and recommends wingsuits from Phoenix-Fly: http://www.phoenix-fly.com