F-15 Computational Subsystem

Abstract

A description of the computational subsystem used in the F-15 air superiority fighter is presented. The con- solidated design approach is discussed in which the computational tasks are divided between the central com- puter and sensor computers. The salient features of the central computer hardware and software design are described. Finally, the multiplex communications system between the central computer and the interfacing peripheral avionics equipment is discussed. purpose of the F-15 weapon system is to deliver air- to-air and air-to-ground weapons on targets that must be detected, identified, acquired, tracked, and destroyed by the pilot using sophisticated sensors and weapons. In the course of an F-15 mission, millions of split-second computations and decisions must be made within the aircraft. The pilot, in ad- dition to flying the aircraft, must monitor the instruments constantly and interpret the readings to insure that the weapon system can accomplish its purpose. The minimization of pilot workload was a prime goal in the design of the F-15. Every decision that could be removed safely from the pilot's tasks was incorporated in a highly integrated computational subsystem. The operations within the subsystem are still at the pilot's command, but he is able to perform his primary tasks with confidence based on reliable, real-time operation of his computational subsystem. The computational subsystem consists of a single central computer and several smaller computers in various sensor and display equipment, as shown in Fig. 1. The central computer, which employs the IBM Advanced Process6r-l (AP-1) com- puter, integrates the overall operation of the avionics. The operational flight program (OFF) for the central computer was developed by McDonnell Aircraft Company and was flight-tested and qualified by both McDonnell and Air Force pilots at Edwards Air Force Base in California.