F-15 S/MTD IFPC fault tolerant design

One of the major requirements for the F-15 STOL (short take off and landing) and maneuver technology demonstrator (S/MTD) was to develop and demonstrate an integrated flight and propulsion control (IFPC) system. The IFPC is a fly-by-wire (FBW) system that replaced the F-15 mechanical flight and engine controls. It was a USAF requirement that the IFPC be fault-tolerant and that loss-of-control not exceed once per 100000 flights. A program goal was that the IFPC meet or exceed the reliability and maintainability of the basic F-15. The authors describe the architecture and redundancy management of the IFPC and the associated aircraft system modifications that created a robust, fault-tolerant, and maintainable flight/propulsion control system. It is concluded that the techniques used to provide the required failure management characteristics for the S/MTD resulted in a system which could withstand a significant number of failures in various parts of the system without loss of aircraft control