Advanced Control System Architecture For The T800 Engine

A state of the art Full Authority Digital Electronic Control (FADEC) system is being developed for the T800-LHT-800 engine by the Light Helicopter Turbine Engine Company (LHTEC) for the U.S. Army's next generation Light Helicopter (LH). The dual-channel control system integrates into a fly-by- wire helicopter via a MIL-STD-1553B communications interface between engine, airframe, and the Engine Monitoring System (EMS). The integrated system takes advantage of redundant sensors previously dedicated to separate functions such as cockpit display, engine control, etc., thus providing an extremely fault tolerant engine control system. Oncondition maintenance is enhanced through integral fault detection logic which isolates system failures to the Line Replaceable Unit (LRU) level. This failure information is then transmi ted to the EMS for retrieval by ground based equipment. Adaptive control concepts demonstrated during the U.S. Army's Adaptive Flight Test Program have been incorporated into the T800 engine control. These concepts include: 1) a high performance power turbine governor that minimizes rotor speed droop and smooths out engine torque recovery, 2) engine surge detection and automatic reconfiguration of the acceleration schedule to preclude repeating surges, and 3) engine failure detection and autorelight following flameout, Engine tests, flight tests, and LH simulator test results have demonstrated the fault tolerance, simple maintenance, and high performance of the T800 control system.