Wing Cuffs

Wing Cuffs

- Rob Mark

“Stalls and spins represent the largest single factor in fatal general aviation accidents.” Surprisingly, this quote wasn’t pulled from the latest FAA news release, but rather from a NASA Langley Research Center newsletter dated April 1977. Forty years later, stall spins and loss of control remain pinned to the top of the National Transportation Safety Board’s Most Wanted List of safety improvements. That doesn’t mean no one has tried to reduce the number of LOC-I fatalities. 

In this month’s How It Works, we look at the wing cuff, a relatively simple concept designed to improve stall spin resistance and take a bite out of GA accident numbers. The wing cuff is a low-cost modification that causes the wing to behave like two separate spanwise sections, each having vastly different aerodynamic characteristics. The leading edge of the wing’s discontinuity then creates solid spin resistance. The inner portion of the wing nearest the root stalls before the outer section nearer the ailerons. As the pilot increases angle of attack to maintain either a specific airspeed or altitude, the inner portion of the wing reaches its critical angle before the outer section. While the inner portion of the airfoil begins to exhibit buffet from the approaching sta