T56 Derivative Engine in the Improved E-2C

Airborne Early Warning for the Navy fleets has been provided for the past 20 years by the Grumman/Allison E-2 Airframe/T56 engine combination. Although avionic capability has been continually updated to meet the increased threat, the airframe and powerplant have seen only minor changes. Projected mission requirements and future avionic system enhancements require payload increases being limited by the power capability of the present T56 powerplant. Of paramount importance in the E-2 carrier deck operation is the single engine rate of climb capability of the aircraft. This paper discusses the logical evolution of a replacement engine for the E-2C — a derivative T56 engine contracted and designated by the Navy as the T56-A-427 — to meet the projected single engine takeoff and other mission requirements. The T56-A-427 provides 24% power and 13% fuel consumption improvements with identical installation interfaces, and substantially improves E-2C performance characteristics across the flight envelope. Furthermore, the paper shows that meeting these stringent performance requirements with a derivative engine results in a low risk development program and an engine with improved maintainability and reliability, which can capitalize on the in-place logistics support base of the T56 — the world’s longest production run gas turbine engine.