All-Electric Fuel and Oil Control System Demonstration on the T55 Engine

Triumph Engine Control Systems developed and demonstrated a new all-electric fuel and oil control system for the Honeywell T55 turbo-shaft engine. The system replaces the current mechanically driven system with an electrically driven system. The new system performed the functions of the existing mechanical controls while also highlighting unique capabilities and advantages. For example, mechanical systems are subject to the energy-wasting constraint that pump flow must be proportional to engine speed. The electrical system removes this constraint by controlling its pumps to deliver only the fuel and oil flow actually needed. The fuel system provides fully redundant pumps, motors, and control electronics, providing enhanced failure accommodation. The developers adjusted control system flow schedules and pressures with software changes, providing great flexibility in development. Triumph demonstrated equivalent or better performance than the existing control system on a T55 engine under test at the US Army's RAPTR test facility.