WASHINGTON — Choosing to replace the F-35’s engine with a next-generation adaptive model could force the U.S. military to buy 70 fewer fighters.
Air Force Secretary Frank Kendall warned of the tough decisions that could come from a change in propulsion for the F-35 at the Defense Press Conference in Arlington, Va., Wednesday.
New propulsion system being developed under the Adaptive Engine Transition Program, most likely for the Air Force’s F-35A, could lead to more power and fuel efficiency for the fighter . The Air Force said adding more power to the fighter would help it handle upgrades in future years.
The price tag to develop and produce AETP could exceed $6 billion, Kendall said. And that could lead to a difficult trade-off.
“If you have several hundred F-35s in your inventory, how many more F-35s are you willing to give up to get the new engine?” Kendall said during a panel at Wednesday’s conference. “It’s an expensive engine. It takes a lot to do development—several billions of dollars. [That] is roughly 70 F-35s. So are you willing to have 70 fewer F-35s to have this engine in the ones you have?
The adaptive engine, versions of which are currently being developed by Pratt & Whitney and General Electric Aviation, uses new technologies such as a third airflow to improve fuel efficiency, thrust, speed, range and handling heat.
Kendall said he hopes the Department of Defense can make a decision on whether to install an adaptive engine in the F-35A as part of the fiscal year 2024 budget, but said it’s not. wasn’t sure yet. Kendall said he, Undersecretary of Defense for Acquisition and Sustainment William LaPlante and Undersecretary of Defense Kathleen Hicks discussed whether to use an adaptive engine.
The Department of Defense must make a choice one way or the other, Kendall said.
“I don’t want to keep spending money on an engine that we’re not going to develop and put into production,” he said. “We just have to make a decision, decide what to do and move on.”
The AETP isn’t the only option the defense industry is working on to improve the F-35’s engine, Kendall said. He didn’t specify which program he was referring to, but Pratt & Whitney — the maker of the F-35’s current F135 engine — has been working on an F135 modernization program called the Enhanced Engine Program.
The industrial base concerns an “overestimation”
Kendall played down concerns about the health of the adaptive engine industrial base recently raised by Air Force Propulsion Chief John Sneden. During a briefing with reporters last month, Sneden said the industrial base was “very thin” and that a decision not to go ahead with an adaptive engine in the F-35 could lead to its “collapse”.
Kendall called the warnings of potential collapse “exaggerated”.
He said it was important to maintain a viable and competitive market for military engines and to find ways to keep multiple companies in that market so they could advance the technology. This is one of the issues being considered as the military determines the way forward for the AETP, he said.
The Air Force’s recent next-generation adaptive propulsion contracts awarded to five companies to develop prototype adaptive engines for its next-generation fighter jets also show the strength of this market’s industrial base, said Kendal. Besides Pratt & Whitney and GE, the Air Force has awarded contracts to Boeing, Lockheed Martin and Northrop Grumman.
The number of engines that will be produced under the NGAP contract — each company’s contract was worth up to $975 million — will be “relatively modest” compared to the needs of the F-35, Kendall said.
The lessons of the withdrawal from Afghanistan
Kendall also referred to the evacuation of Kabul in August 2021 at the end of the Afghan war, in which airmen evacuated approximately 124,000 Afghans, Americans and others over the span of two weeks.
As a result of the evacuation, the Air Force learned how to better maintain and keep planes airborne during future high-intensity airlift operations in austere locations, Kendall said. Artificial intelligence could play a role in this, he said, using a form of condition-based maintenance to track the flight time of various parts on planes performing the airlift, and predicting which ones which may need to be replaced during the operation. may be within reach.
Kendall also said the Air Force has learned it needs better tools to plan such operations to ensure Airmen have what they need, how to properly sequence planes and how to manage. ground operations. Airmen did the job last year, he said, but it was labor intensive and artificial intelligence could play a role in future preparations.
Stephen Losey is the air warfare reporter for Defense News. He previously covered leadership and personnel issues at Air Force Times, and the Pentagon, special operations and air warfare at Military.com. He traveled to the Middle East to cover US Air Force operations.