Structural Analysis And Testing Of ACAP Subcomponents

The purpose of the Advanced Composite Airframe Program (ACAP) is to demonstrate the technological advancement achievable with advanced composite materials and structural design concepts by the design and flight demonstration of an experimental utility helicopter. The primary components developed under the ACAP are the airframe and the landing gear. The subsystems and secondary systems being utilized for the ACAP flight vehicle are those of the commercial S-76 helicopter with certain exceptions defined within the contract. Design support testing of ACAP subcomponents was conducted early in the program to validate the structural design concepts and manufacturing processes and to provide data sufficiently early in the program so that necessary modifications could be incorporated prior to the fabrication of ground and flight test articles. This paper reports the results of analyses and testing of several ACAP subcomponents; the windshield center post pultrusion, the empennage structure, and the cabin roof structure. The testing generally demonstrated adequate strength. Where strength deficiencies were exposed, additional analyses identified the corrective actions required to achieve the strength requirements for the ACAP design.