Flight Path Reconstruction Techniques Applied to Spin Tests

Abstract

This work presents a new approach adopted in the application of flight path reconstruction (FPR) techniques to overcome limitations in the flight test instrumentation (FTI), even when one or more flight test parameters are unreliable or corrupted. The main motivation arose from the necessity of measurement of true airspeed during spin tests, for modeling purposes. However, airspeed measurements become unreliable during spin maneuvers, due to Pitot tube ineffectiveness when subjected to angles of attack and sideslip in excess of 40◦. At first, it is not possible to use this parameter for flight path reconstruction of the spin maneuver, because the unrealistic measurements during the developed spin would affect the entire estimation process. However, the measurements before and after the spin are valid and useful for estimation. The new approach proposed is used not only to separate the useful part of the flight data, but also to obtain reliable estimates of the corrupted parameters during the time intervals at which they were considered unreliable.