Effects of turbulence on bank upsets of small flight vehicles

Abstract

Flight vehicles of different sizes exhibit different responses to turbulence, particularly as a function of wingspan. This report exercises an Excel code, TURBANK, to calculate the stochastic bank characteristics of a vehicle excited by atmospheric turbulence. The lateral responses in ground level turbulence of ten representative vehicles, ranging in size from the 130 ft wingspan Boeing 707 through birds and small UAVs to a micro UAV of 1/2 ft wingspan, are calculated and discussed. Vehicles of less than one foot wingspan exhibit excessive bank response to turbulence. The code will be a tool for determining the factors involving lateral disturbances, which is a critically important flight characteristic for small UAVs. Copyright © 2009 by Peter Lissaman.