Analysis of hover/hovering turn of a complete helicopter configuration using a coupled aerodynamics-flight dynamics solver

Abstract

Loss of yaw control effectiveness has been a common cause of helicopter accidents. Comprehensive analysis of yawing motion and tail rotor control is necessary to reduce the helicopter crash. The authors considers that the analysis of hovering turn is an appropriate starting point as a preliminary research. In the present paper, the trimmed pilot input angle for hover flight was found using the analytic and numerical trim procedures. The pilot input obtained from the analytic trim analysis was used as an initial condition for the hover flight simulation of a complete UH-60 helicopter configuration to accelerate the convergence in the numerical rotor trim. After the hovering flight for a while, the pedal input was given for hovering turn flight simulation. The computed result was compared with the flight test data and the nonlinear analysis result with the dynamic trim. A vortex lattice/panel/vortex particle method was used for aerodynamics simulation, and the simplified flight dynamics approach was used for 1 DOF flight in yawing direction.