Manufacturing Technology Applied to the Prototype XCH-62 Heavy-Lift Helicopter Airframe - the First All-Honeycomb-Primary-Structure Aircraft

In the fall of 1975, the Army's prototype Heavy-Lift Helicopter will roll out and begin ground-testing prior to its first flight early in 1976. The HLH prototype is the first military aircraft to have all of its primary structure fabricated from bonded-honeycomb assemblies. The use of bonded-honeycomb panels for primary structure has reduced the parts count by 23 percent over conventional skin-and-stringer construction, with corresponding reductions in cost and weight. This paper describes the tooling philosophy for the HLH prototype, including extensive use of the Boeing computerised master-dimensioning system for mathematical lofting, the unique design of single-contour, double-contour, and flat-panel bonding tools, and the problems and experience gained in the detail fabrication, processing, subassembly, and final assembly of the bonded structure, some skin panels of which measure 4 feet by 32 feet.