Design and Development of the Fail Operative Automatic Landing System for the Lockheed L-1011

This paper describes the operational characteristics, design processes, and test programs established to produce a “fail-operative” automatic landing system for the Lockheed “TriStar.” The operational characteristics are predicated on the anticipated changes in ATC procedures during the 1970's which may lead to increased automation of the airborne elements. The design processes involve the use of new electronic voting techniques and the consideration of the total airplane systems in view of the critical aspects of failure modes and effects. The test program is outlined and the use of many iterative stages of comprehensive test facilities are described. Conclusions are made that unexpected benefits have been derived by the adoption of the total systems approach.