UH-60 EXTERNAL LOAD HANDLING QUALITIES EVALUATION

摘要

The dynamic motions of external loads are known to have a negative impact on the handling qualities of helicopter/external load systems during hover/low-speed operations. Although criteria have been proposed, currently there are no external load quantitative requirements in the U.S. Army Aeronautical Design Standard for rotorcraft handling qualities, ADS-33. To collect data to support the development of quantitative criteria to address this need, the U.S. Army Aeroflightdynamics directorate has conducted a series of external load flight tests with an EH-60L helicopter at Moffett Field. Four experimental test pilots performed evaluations of three Mission Task Elements from ADS-33E-PRF. These were flown without an external load, and with eight external load configurations (two load weights and four sling lengths). Frequency sweeps of each configuration were also conducted to provide quantitative data. Pilot comments and assigned handling qualities ratings (HQRs) from testing indicate that the effects of external loads on handling qualities are most pronounced with the combination of long sling lengths and large external load weights. Based on the qualitative results, the attitude frequency responses obtained from the frequency sweeps were analyzed and parameters identified that correlate well with the assigned HQRs. Using these parameters, a quantitative criteria has been developed that can be used to predict the hover and low-speed handling qualities of helicopters with external load.