Structural Vs Performance Vs Financial
Nick Lappos opined in a technical paper many years ago that limitations can be grouped into three categories, structural, performance, and financial. Structural limitations are physical limitations established with sufficient margin to insure the structural integrity of the vehicle throughout its flight envelope. Performance limitations are established based on installed engine power limitations and rotor system performance. In all cases, the published limitations are demonstrated by the manufacturer and verified by the certifying agencies. Lastly, financial limitations are just was they imply. The manufacturer has determined that even though the vehicle is capable of operations in excess of those already established it would not be cost effective to test and certify the vehicle to these increased limitations. This is the case when customer requirements do not dictate any requirement for and increase. The S-76A VNE chart is a good example. VNEs at higher cruise altitudes were established within the engine power limitations of the 250-C30 engines. When the B was certified those limitations were not lifted even though the B had a dramatic increase in installed power.
Some place in the bowels of my home office I have a copy of Nick report and will pass it on when located.