Five-hole flow angle probe calibration from dynamic and tower flyby maneuvers

Flight-test and data analysis techniques applied to calibrate the static pressure measured by pitot static systems and the flow angles measured by a five-hole probe mounted on a noseboom are described. Dynamic maneuvers with rapid variations in the aircraft motion are analyzed by application of parameter estimation techniques based on the output error method to calibrate the angle of attack and angle of sideslip. A complementary approach based on the Kalman filter technique is applied to a wind-box maneuver to calibrate the flow variables. The tower flyby maneuvers are analyzed using the classical approach of altitude determination through geometrical evaluation of photographs, and accurate information is derived from redundant sources to calibrate the pilot static system, The investigations showed that the static pressure measured by aircraft-installed pitot static system is accurate, sufficiently whereas that measured by an additional sensor mounted on the noseboom required speed-dependent correction. The flight estimated sensitivity factors for the flow angles measured by the five-hole probe agreed reasonably well with the manufacturer's specifications subject to corrections for biases resulting from misalignment and time delays caused by the recording equipment.[PUBLICATION ABSTRACT]