Helicopter Response and Pilot Performance Metric in the Shipboard Landing Environment

摘要

An experiment consists of a remote-controlled T-REX 600E Pro helicopter piloted above an underway 108 ft (32.9 m) research vessel's flight deck to analyze the effect of Re = 6.2 x 10~5 turbulent ship air wake on helicopter angular motion. The motion is measured by an inertial measurement unit sensor mounted on the helicopter transmitting variably-spaced data in a 3-D Cartesian reference frame. Data are collected with the helicopter in scaled locations above the flight deck which closely match actual takeoff/landing positions of U.S. Navy H-60 helicopters above flight decks of air-capable ships. This method is both an indirect way of qualifying the flow field and a practical way of measuring the actual effects of ship air wake turbulence on rotary-wing aircraft. Fourier analysis is performed with the Welch power spectral density estimate on helicopter angular velocities to determine predominant frequencies of motion. The spectra of pilot inputs in roll, pitch and yaw were found to have cutoff frequencies of 0.5-0.7 Hz, which agree well with full-size helicopter pilot autospectra. A 3 Hz helicopter angular rate response is noted; the source of this disturbance is due to characteristic turbulent scales in the wake interacting and engaging a yaw trim gyro which enables the helicopter to hold heading. A novel method for evaluating pilot performance in full size helicopter launch and recovery evolutions is presented with the data from five separate flights. This new method of visualizing a helicopter's motion provides an immediate, quantifiable way to identify both pilot performance and technique. Furthermore, this method provides a means to more objectively evaluate the difficulty of shipboard launch and recovery evolutions.