Technical Evaluation Report On The Flight Mechanics Panel Symposium On Rotorcraft Design For Operations

The expanding roles of the helicopter and the intensified threat perceived by its potential users have led to proposals for future rotorcraft with characteristics significantly different to existing types. The resulting rapid evolution of rotorcraft configurations, in response to user demands, now requires a translation into design criteria to permit aerospace R & D community to provide appropriate and cost effective responses to these demands. The objective of this symposium was to explore the impact of operational needs on the evolution of rotorcraft design. The result will be to provide a review of the present status of rotorcraft design and to identify priorities and neglected topics. Three specific issues were central: 1) The translation of operational mission requirements into design criteria; 2) The evaluation of techniques to incorporate user defined needs into the design and methods of test and verification; and 3) The identification of design areas where unusual or new user needs are demanding special or radical features. Keywords: Rotary wing aircraft. (kr).

Abstract.

This report presents a review and evaluation of the Flight Mechanics Panel Symposium on Rotorcraft Design. It is apparent that the levels of technology of both military and civil helicopters now entering service are very high. It is also evident that the highly specialized requirements of the military aircraft have caused the military helicopters to be less useful for direct application to civil markets. Of prime concern is the inability to produce derivatives of the large military transports for use as commercial airline helicopters. It was clear that the reason for this was the complex, costly civil certification required combined with a limited market as seen by the manufacturers.

Flight in turbulence impacts the operation of all classes of aircraft. Turbulence affects aircraft design and operations in many ways. The aircraft's structure must be designed to handle loads induced by large discrete gusts as well as the spectrum of loadings which occur throughout the life of the aircraft. Operations in rough air affect passenger comfort as well as the control of the aircraft, either manually or through automatic systems. Thus flight in turbulence requires an interdisciplinary approach to determine the true inputs to the aircraft, the development of means to include these inputs in the structural design and the control system design, and the establishment of operational procedures to minimize the effects of turbulence on ride quality and safety.

This report evaluates the AGARD Flight Mechanics Panel Symposium on Stability and Control held from 25-28 September 1978 at Ottawa, Canada. The primary conclusions of the report are that the technology exists to permit application of CCV and active control concepts to operational aircraft; however, questions remain concerning the operational need and the cost effectiveness of many of the concepts that are technically feasible. The main factors impeding implementation of CCV and active control concepts are cost, reliability and maintainability.