COMPARISON OF AIRSPEED CALIBRATIONS EVALUATED BY THE ACCELEROMETER AND RADAR METHODS

A calibration of the pitot-static airspeed installation on a jet fighter airplane was made to compare the accelerometer method of deter-mining static-pressure error with the radar method. The radar method makes use of measurements of static pressure recorded in the airplane and of geometric height as determined by recording radar-phototheodolite equipment on the ground. In the accelerometer method, free-stream static pressure is computed from measurements of pressure, measurements of temperature, and changes in geometric height determined by integrations of accelerometers carried by the airplane. The tests included shallow dives up to a Mach number of about 0.80 with pull-ups of about k, 3> and 2g normal acceleration. The results of the tests indicated that, for vertical plane maneu-vers, the accelerometer method may be used as an alternate to the radar method. Although the accelerometer method requires airplane instrumen-tation of fairly high precision, this equipment may be more generally available than the radar equipment