6.2 - Overcoming Instrumentation Limitations in Spin Tests Using Flight Path Reconstruction Techniques

Event
etc2014 - 34. European Telemetry and Test Conference
2014-06-03 - 2014-06-05
Nürnberg
Chapter
6. Methods & Standards
Author(s)
J. Dias - IPEV - Instituto de Pesquisas e Ensaios em Voo, São José dos Campos, São Paulo (Brazil)
Pages
106 - 111
DOI
10.5162/etc2014/6.2
ISBN
978-3-9813484-7-7
Price
free

Abstract

This work presents the results obtained by application of flight path reconstruction (FPR) techniques to flight data collected during spin tests. The FPR methodology allows in-flight calibration of several sensors, because it takes advantage of the kinematical redundancy between parameters that usually exists in most flight test instrumentation (FTI) projects. For the particular case of spin tests, the aircraft experiences high angles of attack and sideslip, which may extrapolate the calibration limits of the vanes. Besides that, the Pitot tubes measurements become unreliable when subjected to extreme incidence angles, which corrupt airspeed measurements during the spin. However, measurements obtained before the spin entry and after spin recovery are still valid. Therefore, using the FPR, airspeed measurements are integrated along the maneuver, in order to match the data before and after spin, so that the airspeed during the spin is obtained. This methodology also provides calibration for airflow angle vanes and the values of biases that affected the accelerometers and gyros. In this work, FPR was applied to spin tests performed with three different aircraft, featuring different FTI projects. Despite the different limitations on each FTI project, the FPR was able to provide good results in all cases analyzed.

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