Development and flight evaluation of automatic flare laws with improved touchdown dispersion

Abstract

The paper describes the development and flight testing of automatic landing flare laws with improved longitudinal touchdown dispersion. The major sources of touchdown dispersion in current control laws and design objectives of this equipment are discussed. A ground-speed adaptive sink-rate control law and a specified flare trajectory control law were selected for development; the performance of resulting flare laws was evaluated by simulations and flight testing on the NASA TCV B-737 aircraft. These flare laws showed substantial improvement in longitudinal touchdown dispersion, when compared to a more conventional flare law used previously.