Flight test of V-22 Hover Mission Task Elements in Natural Winds

摘要

The V-22 Osprey tiltrotor low-speed flight envelope was developed primarily on the basis of paced criticalrnazimuth testing, coupled with paced pedal kicks to measure transient control margins. In order torndemonstrate that the low-speed hover flight envelope was acceptable in real-world conditions, a flight testrnprogram was conducted to measure handling qualities ratings (HQR) for 7 mission task elements (MTE) at 4rnwind azimuths in 3 wind bands. Hover MTE tests such as those presented in ADS-33, and in previous flightrntests of the V-22 and other vehicles, were developed and flown in low- or no-wind conditions. On the otherrnhand, shipboard tests in winds typically focus on a limited number of operations in the presence of large,rnthree dimensional air currents caused by the ship that are not translatable to land-based operations. Thisrnpaper explores the approach taken to extend MTE testing to include natural winds up to the highest speedsrnpermitted for operations of the V-22. In addition to the test results, the creation of the MTE tolerances andrnthe design and implementation of the test course are discussed. Because the aircraft mission does not changernas the wind speed increases, the task tolerances were the same as those for no-wind conditions. HQRs werernexpected to drop as wind speed increased and the pilots had more difficulty in performing precision tasks.rnFor both the MTE tolerance and the test course layout, compromises were made to increase the efficiency ofrnthe test, specifically to minimize flight time and to take advantage of wind and weather conditions. The keyrnlesson learned is that defining the V-22 low-speed envelope through paced testing and control marginrninvestigations is adequate, except for vertical landing and takeoff in winds. In addition, a practical andrnefficient test course was designed and used in the tests. However, finding natural winds up to or beyond thernflight envelope limits is difficult and time-consuming. Overall, MTE testing in natural winds was found to bernpractical and added to our knowledge of the V-22, but the test was complex and may not be necessary for allrnaircraft.