The JT9D Engine Control System

The JT9D turbofan engine, soon to be in airline service on the next generation of advanced jet aircraft, will incorporate the Hamilton Standard JFC 68 main fuel control and EVC 3 engine vane control. Now in production, this control system embodies advanced control technology while retaining the basic advantages of present operational systems. Its specific advantages are improvements in weight, performance, reliability, and durability over present commercial jet engine control systems. This paper presents a discussion of the design philosophy used in creating the system, a description of the system and some advanced techniques used in its development.