An in-flight experiment was conducted to evaluate certification factors for decelerating approaches for rotary wing aircraft in instrument meteorological conditions (IMC). The goals of the experiment were to determine: (1) limiting factors for crosswind regulation; (2) acceptable combinations of flight director and autopilot functions; and (3) necessary characteristics for the collective flight director. It was found that both the wing-low, and the turn-coordination (crab) methods of crosswing regulation were acceptable for approaches down to 50 feet altitude and 25 knots ground speed. It was also found to be acceptable blend from the crabbed approach during the deceleration. The experiment only considered the ICM portion of the approach so that field of view at breakout considerations should not be factored into results of this study. Acceptable performance and pilot workload was achieved with a two axis flight director (pitch and roll), and raw data collective, as well as all of the more sophisticated configurations. Raw data approaches (no flight director) were found to be unacceptable. The augmentation consisted of low gain rate damping for all of the tested configurations.
Flight Test Investigation of Flight Director and Autopilot Functions for Helicopter Decelerating Instrument Approaches
1989
58 pages
Report
No indication
English
Aircraft , Aeronautics , Automatic flight control , Automatic pilots , Deceleration , Flight tests , Helicopter performance , Instrument approach , Workloads (Psychophysiology) , Air traffic control , Augmentation , Ground wind , Instrument flight rules , Instrument landing systems , Man machine systems , Tracking (Position)