FLIGHT INVESTIGATION OF VARIATIONS IN ROTORCRAFT CONTROL AND DISPLAY DYNAMICS FOR HOVER

This paper describes a flight investigation of the handling qualities issues associated with variations in display dynamics for varying levels of vehicle augmentation. The experiment was conducted on the NASA/Army CH-47B Variable-Stability Research Helicopter using its model-following control system and a color, panel-mounted display. A display law design method developed and flight tested previously was refined and expanded to account for guidance effects. Specifically, for rate, attitude, and velocity command vehicle response types, both integrator-like and gain-like display controlled element dynamics were evaluated in two hovering tasks conducted in simulated zero-visibility conditions. The tasks were performed both with and without automation of the vertical and directional axes to assess the impact of divided attention on performance and work load. Quantitative and subjective data describing the pilots' ability to perform the tasks were collected and analyzed, and pilot-vehicle-display dynamics were identified. Results indicated that gain-like display dynamics were generally preferred and resulted in better inner-loop tracking and higher inner-loop crossover frequencies, while not degrading outer-loop position performance.