Accession Number:



Ground Based Simulation Evaluation of the Effects of Time Delays and Motion on Rotorcraft Handling Qualities

Descriptive Note:

Final rept. 16 Jul-17 Aug 1990

Corporate Author:


Report Date:


Pagination or Media Count:



An exploratory simulation was conducted on the NASA Ames Research Centers Vertical Motion Simulator VMS to evaluate the effects of simulator characteristics on handling qualities for performing hover and low-speed tasks in a helicopter. The primary focus of the study was on subjective assessments of the variations, based on Cooper-Harper Handling Qualities Ratings HQRs, rather than objective measures of pilot performance. Effects of variations in the three major elements of the simulation--the motion system, visual system, and math model--were evaluated. Seven precision and aggressive low-speed Mission-Task-Elements were performed. All tasks were Level 2 average HQR worse than 3.5 fixed-base for the baseline helicopter, which was designed to provide Level 1 handling qualities in the real world. Addition of motion improved ratings 12 to 2 points, resulting in Level 1 handling qualities for most tasks. Tradeoffs in motion acceleration gain and washout break frequency were evaluated with two sets of motion washouts. There was a preference for reduced washout frequencies resulting in improved phasing between the visual and motion responses at mid helicopter, handling qualities, simulation, time delay, motion system to high frequencies, at the sacrifice of onset gain for the precision tasks. Conversely, there was a slight preference for increased onset gains at the sacrifice of visualmotion phasing for the aggressive tasks. The effects on handling qualities of a visual delay compensation algorithm were investigated by three pilots.

Subject Categories:

  • Helicopters
  • Computer Programming and Software
  • Human Factors Engineering and Man Machine Systems

Distribution Statement: