TABLE OF CONTENTS Testing for rotorcraft aeroelastic and aeromechanical stability continues to be a necessary tool for the successful development of new designs. Although aeroelastic analyses have continued to develop with increased breadth and sophistication, they are still not accurate enough to be used routinely as design tools for the analyses of man-rated aircraft. Not only must these analyses be validated experimentally, but instability issues inherent in new rotorcraft concepts must be identified as a guide to new or continued aeroelastic methodology development. Furthermore, although testing of a prototype at full scale for aeroelastic stability is still performed, it is with the intention of providing proof-of-design validations rather than exploring new stability issues or sizing the design parameters to preclude the occurrence of any possible instability. Such testing at full scale is typically very cost prohibitive and is best done only where absolutely necessary. Thus, multiple reasons exist for testing rotorcraft for aeroelastic instability at model scale.
For such testing to have relevance to full-scale behavior, it must be performed with the correct attention to the scaling of the appropriate parameters, both with the rotor and the airframe. Such scaling is generally an exercise in knowing which issues can be compromised and which cannot, for it is impossible to scale everything at scale factors of anything less than unity. Construction of aeroelastic models requires attention to issues of practical construction technique. Often a properly scaled model can end up being literally impossible to fabricate for certain important ranges of...
