Static Design Flight Loads with Fly-By-Wire Technology

With the incorporation of Fly-By-Wire (FBW) technology as the primary rotorcraft control system, a new dimension to flight loads analysis is opened. Suddenly, the aircraft flight dynamics are not solely affected by the pilot control inputs, but are a combination of the control inputs and the underlying FBW flight control laws. This adds complexity to the development program, but the advantages associated with the technology far outweigh the additional effort. The purpose of this paper is to show the differences between developing static design flight loads using a FBW flight simulation vs. a legacy mechanical flight control system. It will also address the impact on maneuver methodology to meet design requirements. Finally, it will discuss how the overall design process differs from that of a mechanical flight loads program, highlighting the logistical challenges which are a result of incorporating a FBW control system. The content of this paper is drawn from experience gained and data generated on the UH-60M Modernization program, a derivative program of Sikorsky's BLACK HAWK helicopter line which will be the first of its kind equipped with Fly-By-Wire technology.