Extended Range Operation of Twin-Engine Commercial Airplanes

This paper discusses safety and reliability considerations that were examined in the development of new guidelines for commercial use of twin-engine airliners for extended range operations. The 767-200ER airplane is referred to extensively because it was the first twin to be approved for extended range operations under the new guidelines.

The key technical issues involved are engine reliability and the ability of the propulsion and airplane systems to provide safe, sustained operation during the anticipated time period of the diversion after an inflight engine and/or system failure. Airline operational considerations for extended range operations with twins are reviewed, as well as the future impact on the traveling public and the airline industry brought about by the service introduction of new technology twins.