DC-9 Super 80 Digital Flight Guidance System Integrated System Testing

The DC-9 Super 80 Digital Flight Guidance System incorporates continuous system monitoring, inflight failure logging, and extensive test capability both for troubleshooting problems and for verifying the system operational status after maintenance action. This paper will discuss the evolution of Built In Test Equipment, its implementation and use in the DC-9 Super 80, some problems encountered in developing such a system, and speculation as to how system testing will be improved on future aircraft.