Honeywell’s HTS7500 turboshaft has been selected as the powerplant for the Lockheed Martin Sikorsky-Boeing Defiant X helicopter, which is a contender for the U.S. Army’s Future Long-Range Assault Aircraft (FLRAA) competition. Plans call for FLRAA to replace the service’s UH-60 Black Hawks from 2030.

Honeywell’s most advanced military engine to date, the HTS7500 builds on the proven T55 engine that powers the CH-47 Chinook. The new engine is structurally similar to the T55, which eases the training of maintainers and allows them to use the same tools. However, technological advances have provided a 42 percent increase in power output compared with the T55-714A, while it weights less than any turboshaft in its 7,500-shp class. A modernized control system provides a secure flow of engine data, enhancing engine health monitoring while improving operational capabilities and reducing life-cycle costs.

Lockheed Martin Sikorsky-Boeing has flown its SB-1 Defiant demonstrator since March 2019 powered by a pair of T55s.