ANALYSIS OF PILOT INDUCED OSCILLATIONS

Document Type : Original Article

Authors

1 Eng. Airforce Academy Belbis.

2 Ass Prof.Aeronautical Dept., M.T.C., Cairo.

3 Prof. Arab Mar. Academy Alexandria.

4 Prof.Aeronautical Dept., M.T.C., Cairo.

Abstract

Ever since manually controlled flight of powered aircrafts, pilots have experienced pilot induced oscillations (PIO). PIO problem is one in which an oscillation of the aircraft occurs, that is difficult or even impossible for the pilot to stop. A central characteristic of the phenomenon is that the airplane is stable both stick-fixed or stick-free, hence the name pilot induced oscillation. The presented work studies the effect of pilot and aircraft parameters on pitch tracking performance. Also conditions that bring the pilot-aircraft system to instability were discussed. An appropriate pilot model convenient for PIO analysis is selected and a closed loop analysis of pilot-control system-aircraft has been done in time domain. The pilot dynamics was found to be the most significant factor of PIO. When the pilot model includes neuromuscular system dynamics, the pilot gain required to sustain an oscillation was found to be. 55% of that value with the pilot as a pure gain.