Development and Flight Testing a Simplified Fixed Shaft Turboprop Flight Control System

Adaptation of fixed shaft turboprop engines to business and utility aircraft requires drastic simplification of the control system as compared to transport turboprops. The AiResearch TPE331 engine incorporates a variable low pitch stop controlled thru mechanical linkage to achieve both simplified control and also reverse thrust. Control of the system utilizes a cam cut to match airplane-engine-propeller flight characteristics. Flight testing in aircraft varying from a converted B-26 test bed to slow STOL aircraft was used to verify calculations and develop control system, negative torque system and general engine development.