Some Effects of Varying the Damping in Pitch and Roll on the Flying Qualities of a Small Single-Rotor Helicopter.

摘要

Flight-test measurements and pilots opinions are presented of the longitudinal flying qualities and lateral control characteristics of a small single-rotor helicopter. In these tests the damping of the helicopter in pitch and roll was varied by means of a rate-sensitive automatic-control device from the amount present in the helicopter with the device inoperative to nearly three times that amount. Longitudinal stability and control characteristics which were unsatisfactory with the device inoperative were improved by increasing the damping of the helicopter and were judged as satisfactory when the damping was approximately doubled by the device. The tests tended to confirm the proposed requirements of NACA TN 1983 that, for satisfactory stability, the curve for normal acceleration in a pull -and-ho id maneuver should become concave downward within 2 seconds of the start of the maneuver. The largest amount of damping tested resulted in correspondingly reduced rates of roll. Although noticeably low, these rates, however, seemed adequate to the pilots for normal flying.