Sensitivity Study Of A Small Maritime Rotary UAS Operating In A Turbulent Airwake

This paper describes helicopter model development work which will be used in the next stage of a research project to establish flying qualities requirements for Unmanned Aircraft Systems (UAS) operating in Maritime Environments. A new T-REX helicopter model, classed as a Mini UAS, has been built in the FLIGHTLAB simulation environment. A brief description of the model set up is provided alongside some of the core model parameters. A simple rotor optimization study was completed to assess the rotor for both hover and 30knots airspeed; the rotor parameters chosen were found to be a good compromise between these flight conditions. A frequency response analysis was also completed and the results compared to two other aircraft models; an RMAX helicopter and an aircraft similar to an SH-60B (Seahawk). These aircraft were placed in an unsteady ship airwake to assess the effect of turbulence with decreasing aircraft size. Although the smaller aircraft exhibit higher bandwidth in pitch and roll response, they were found to experience significantly larger disturbances in translation and rotational accelerations. This can be attributed to their reduced mass and inertia characteristics. © 2015 by the American Helicopter Society International, Inc.