Loop separation parameter - A new metric for landing flying qualities

Abstract

Loop Separation Parameter is a metric used to evaluate the longitudinal flying qualities of aircraft in the landing flight phase. It combines simple pilot models with classical root locus and frequency response methods to predict Cooper-Harper pilot ratings for aircraft in the landing phase. Loop Separation Parameter was originally developed using fighter-type aircraft flight test data; in this paper the concept is extended and shown to be a good tool for predicting pilot ratings for large bomber, transport, and highly augmented Space Shuttle configurations. Loop Separation Parameter anticipates the tendency for and predicts the frequency of pilot-induced oscillations. The effects of control system time delay and altitude lag time constant are discussed. It is recommended that Loop Separation Parameter be included in the Flying Qualities Handbook. .