Speed stability and the landing approach with an appendix of avro 707A longitudinal characteristics

Abstract

Summary. The effect of speed stability on pilot workload and accuracy on the approach has been investigated with the Avro 707A research aircraft. Speed instability was simulated by a reversed autothrottle which applied thrust in response to changes in airspeed, or in airspeed and incidence. No correlation was found between the speed stability parameter and the accuracy achieved in speed holding and flight path control. The pilot's throttle usage, however, varied consistently with the speed stability time constant, and was little affected by the type of talkdown control used. Marked changes in throttle usage corresponded well with pilots assessments of the difficulty of the task. Results of flight measurements of the longitudinal characteristics of the aircraft in the approach configuration are also included in an Appendix.