Nacelle Control Augmentation for Tiltrotor Flight Directors

Flight directors and autopilots have been successfully integrated into fixed and rotary wing aircraft for many years. Flight directors perform the basic task of translating flight guidance commands into a logical set of display symbology. The pilot responds to the display symbology and applies control system inputs to guide the aircraft along a desired flight path. A principal flight director design objective is to provide the pilot with precise flight path control and low workload, particularly when operating at night and/or in Instrument Meteorological Conditions (IMC). This paper discusses limitations of standard flight director symbology for the tiltrotor application and a design approach to supplement standard flight director symbology with nacelle control augmentation to accommodate the unique control characteristics of tiltrotor aircraft. An overview of the MV-22 tiltrotor flight director system is provided along with a description of three candidate types of nacelle control augmentation that were evaluated using man-in-the-loop simulation at the Boeing Flight Simulation Lab (FSL). This paper summarizes the results of an engineering trade study conducted to determine a nacelle control augmentation design approach for the MV-22 flight director system.