Flight path generation for a helicopter in tail rotor failure condition

Abstract

The objective of this study is to generate viable flight trajectories for a helicopter with a failed tail rotor. A generic helicopter model using the FLIGHTLAB software is utilized for tail rotor failure simulation. For a conventional helicopter, there is a certain forward flight speed threshold, above which the vertical tail is sufficient to generate the required anti-torque during forward flight. Tail rotor failures above and below this threshold speed are treated in simulations. Optimal trajectories that brings the helicopter from autorotation to level flight for low speed failures; and from level flight to a predefined location for high speed failures are found. The path generation process is performed in the MATLAB environment with an open-source trajectory optimization tool, OptimTraj. The trajectories are obtained for different scenarios by using linear system dynamic models as constraints.