The Assessment of Rotary Wing Aviator Precision Performance during Extended Helicopter Flights

To insure the most effective utilization of his aviation resources, the rotary wing flight commander requires information which describes how extended flight time affects the operational capability of his flight crews. In response to this requirement, the US Army Aeromedical Research Laboratory has conducted an investigation of the man-helicopter system performance during five days of extended flight. The current report describes the changes in pilot performance and aircraft stability on one of the maneuvers performed during the large scale fatigue investigation, the stabilized three-foot (.91 meter) precision hover. The results obtained during the current examination strongly suggest the occurrence of a learning effect across the first day of extended flight. The most stable hover performance was observed during the second flight day. By the third flight day, pilots attempted to maintain high quality precision hovers through an increase in the number of control inputs. Results obtained on the fourth day of flight suggest that the pilots have shifted their control technique from active control of the helicopter to a more passive strategy of responding to observed error.