Hingeless Rotor Dynamics in Coordinated Turns

Abstract

This paper describes the results of a numerical study of the aeroelastic stability and response of a soft-in-plane, hingeless rotor helicopter undergoing a coordinated steady turn. The combined effects of turn rate, aircraft speed, flight path angle, and direction of turn are discussed. The use of analyses valid only for straight flight is examined. The results indicate that steady level turns stabilize the lag modes but may destabilize some flap modes. Descending turns are destabilizing and may limit the maneuver envelope of the helicopter.