AETP program should boost F-35 and B-21 bomber engines by 10-20% thrust and 25% fuel efficiency in mid-2020s

Lt. Gen. Chris Bogdan, who heads the F35 joint program office, said at last week’s Air Force Association conference that the “mid-2020s” is when the power plant on the joint strike fighter could be refreshed, whether through improvements to the Pratt & Whitney F135 design currently used or through a new engine design from another competitor.

“I would expect … that somewhere in the mid-2020s much of the work being done in the labs right now with our industry partners will find its way onto the F-35,” Bogdan told an audience Sept. 21. “Whether it finds its way onto the F-35 in the current engine or some modified engine remains to be seen, but we do fully expect in the mid-20s to include some advanced technologies on engines.”

The Air Force is currently funding the early stages of the Adaptive Engine Transition Program (AETP) competition, with both Pratt and General Electric Aviation participating. The goal of AETP is to see if the companies can successfully add a third stream of air inside the engine. The program’s goal is to “demonstrate 25 percent improved fuel efficiency, 10 percent increased thrust, and significantly improved thermal management,” according to an Air Force statement.

Both companies received contracts worth $1.01 billion over the summer to fund the research under AETP, with a period of performance ending in September 2021

Theoretically, engine improvements could also be rolled into the B-21 Raider bomber, which is expected to enter production by the mid-2020s. Pratt & Whitney is the engine supplier on the program; and although neither they nor Northrop Grumman, the prime on the B-21, have said what engine is being used, speculation is that some form of the F135 engine will power the bomber.


SOURCES – GE, AETP, Breaking Defense