Handling Qualities And Flight Performance- Implication Of The Operational Envelope

Flying qualities and flight performance are two of the most important aspects in helicopter design and operational use. Guarantees of adequate characteristics must be given and substantiated across the total operational envelope. Both civil and military regulatioris are, in many cases, no more than guidelines, which have to be matched with the operator requirements and transferred into engineering parameters. The paper discusses the impact of the operational conditions on the subcomponents and presents important implications for the layout and design of the aircraft. The substantiation of handling qualities and flight performance at the critical loading (weight, c. g. ) and atmospheric (altitude, temperature) conditions is essential. Modern analytical methods are now able to cover the majority of these aspects, however, flight testing is very often mandatory. Various test campaigns with the MBB helicopters BK 117 and BO 105 LS at some of these extreme conditions (altitude up to 22000 ft, temperatures of -45 to + 50° C) are presented and the establishment of the operational boundaries is demonstrated.