GROUND EFFECTS COMPENSATED REAL TIME AIRCRAFT BODY ANGLE OF ATTACK ESTIMATION

Disclosed is a method of and an arrangement for generating a ground effects compensated aircraft body angle of attack signal. The disclosed method includes converting an aircraft pitch rate corrected alpha vane signal to a free air body angle of attack signal that is calibrated to the type of aircraft that employs the invention for the two conventional landing flap settings. The free air body angle of attack signal then is processed to obtain an alpha vane correction signal that represents ground effects compensation that would be required at zero altitude (aircraft touchdown). The zero altitude alpha vane correction signal is then multipled by an altitude scaling signal and converted to a ground effects compensation signal that is applicable to the then current altitude of the aircraft. The ground effects compensation signal then is summed with the free air corrected body angle of attach signal to provide the ground effects compensated body angle of attack signal of the invention.