Air Force abandons new F-35 turbines

The Air Force has confirmed that it will abandon plans to build a new engine for its F-35 fleet and have opted to upgrade their Pratt & Whitney engines to allow their planes to use future weapons.

The Air Force announced their decision Monday as part of the Air Force’s 2024 budget request. Air Force Secretary Frank Kendall said the decision was mainly a financial one.

“We were not able to fund the AETP,” or Adaptive Engine Transition Program, Kendall said. “We needed something that was affordable, and that would support all the variants.”

The Air Force will now fund Pratt’s proposed “engine core upgrade”: improvements that will enable the existing F135 engine to create more electricity and cooling for tomorrow’s weapons. The F-35A, the variant used by the Air Force and most foreign customers, will receive the upgrades as part of its Block 4 upgrade.

General Electric and a Pratt-led team were hired by The Air Force to develop engine concepts that could compete to become the next F-35 engine. General Electric said its XA100 adaptive engine, which began testing last year, would offer more thrust while burning less fuel.

Kendall has said building a brand-new engine would have cost in excess of $6 billion, which would result in The Air Force being able to buy fewer F-35s.

Kendall did acknowledge that cost wasn’t the only decision they took into consideration. The Air Force was the only service “seriously interested” in the adaptive engine, he said, stating that it would have been “very difficult, if not impossible” to put it on the Marine Corps’ F-35B variant, which has a large lift fan which allows the aircraft to take off from very short runways and land vertically. 

If adaptive engines were cheaper, it’s possible the Air Force would have included it in its budget request, however “we couldn’t get there,” Kendall told the media on Friday ahead of the budget rollout. The service wants to spend $254 million in 2024 for the engine upgrade program.

The decision means Pratt, a subsidiary of Raytheon Technologies, will receive decades of sustainment contracts. In October 2021, Raytheon CEO Greg Hayes said he doubted the Air Force had enough money to fund a whole new engine.

In response to the decision, GE said that this budget request “fails” to consider the need for “revolutionary capabilities that only the XA100 engine can provide by 2028.”