The Aeronautical Design Standard ADS-33C is a proposed US Army/Navy handling qualities speeification for rotorcraft. The DLR a t Braunscbweig has condueted a partial evaluation of the quantitative fonvard flight criteria of the ADS-33C by flight testing an unaugmented BO 105 helicopter. This paper describes the night test and evaluation methods used to obtain the oarameters needed for determinine handline aualities levels. Aonlieahilitv and reoeatahilitv of the criteria are -0 .. . also discussed. Handling qualities parameters that augment existing handling qualities databases are provided. Finally, some problem areas are identified and improvements are proposed.

No abstract

No abstract

No abstract

A research investigation has been conducted on the sects of pitchdue-lo-mll and roll-due-to-pitch cmss coupling on helicopter handling qualities while performing a forward flight (60 knots) mll axis tracking task. Conducted under the USlGerman Memorandum of Understanding (MOU) for Cooperative Research in Helicopter Aeromechanics, this study involved complementary use of a NASA-Ames ground-based simulation and two in-flight simulations using DLR's variable-stability HO 105. The results show that for a roll tracking task, the c u m n t timedomain pitch-mll cross coupling criteria d w s discriminate against unacceptable coupling from basic control, rate, and combined control-rate coupling. However, this criteria format does not discriminate against w a s h e d a~t coupling which can occur in helicopters with feedback contml systems. In addition, the data suggests tightening in the ADS33 Level 1-2 boundary, and the four-second window specified for obtaining compliance data may not be suited for highly agile helicopters. A newly pmposed frequency-domain criteria offers more comprehensive coverage Ulat shows conqistency for all types of coupling investigated. An additional benefit is that the required frequency-domain data can be obtained from the bandwidth tests and analysis, thus d u c i n g compliance flight time by eliminating specific pitch-roll coupling tests.