Patent ID: 8090485

Claim:
A method for detecting faulty low frequency persistent oscillations signals generated by a Flight Control System malfunction that causes faulty persistence aircraft surface oscillations comprising: sensing flight parameters including the group consisting of Yaw Rate, Roll Rate, Pitch Rate, Angle of Attack Rate, Angle of Attack, Sideslip Angle, Mach Number, Airspeed, Dynamic Pressure, Flap Angle, Slat Angle, Horizontal Stabilizer Position, Rudder Position, and Elevator Position; computing a tail load estimate signal by means of formulae and tables whose inputs are said flight parameters; submitting said tail load estimate to a band-pass filter to provide a filtered tail load estimate signal; integrating said filtered tail load estimate signal with a first integration function to provide a first integration result, with a second integration function to provide a second integration result and with a third integration function to provide a third integration result; comparing said first integration result with a first threshold; comparing said second integration result with a second threshold; comparing said third integration result with a third threshold; and detecting an oscillatory fault occurrence as per each of said comparisons.