A New F-35 Engine May Not Be Affordable for the Air Force

While the U.S. Air Force is looking for an adaptive engine to deliver power as well as fuel efficiency for its future aircraft, building a new and advanced engine for F-35's might become too expensive for the Air Force, Greg Hayes, CEO of Raytheon Technologies, told analysts during a recent call.

As part of its Future Initiatives, the U.S. Air Force is looking to develop flight-ready adaptive engines that use three streams of air. Conventionally, jet engines use two streams of air but the U.S. Air Force believes that the third stream of air, if available, can be modulated during flight to deliver additional thrust during combat or for higher fuel efficiency during the cruise. It has initiated the Adaptive Engine Transition Program (AETP) to develop airpower with increased range, better thermal management in its aircraft, and reduce tanker demand during missions.

As part of its AETP, the Air Force awarded $1 billion contracts to Raytheon Technologies and General Electric (GE) Aviation in 2016 to develop these advanced engines for its F-35 aircraft, its mainstay in the future as the F-16's head for retirement. 

Built by Lockheed Martin, the stealth-capable F-35s are also being used by the Marine Corps and the U.S.Navy in slightly different configurations, known as F-35Bs and F-35Cs, respectively. The former also features Short/Vertical take-off and landing (S/VTOL) capabilities whereas the F-35Cs are modified to be operated on aircraft carriers. Neither of these forces is likely to favor the engine developed under the AETP which means that the Air Force will have to foot the entire bill of its development. This is what Hayes was referring to during the call when he said that the engines would become 'unaffordable' for the Air Force. 

Defense News reported that GE Aviation's AETP engine is still under testing but it is being designed to work with F-35A as well as F-35Cs. Raytheon Technologies owns Pratt and Whitney, the makers of the F135 jet engines that are currently being used on the F-35s, and has also offered to upgrade the current engines so that they offer improved cooling as well as thrust but not at the costs associated with building a brand new engine.

With F-16s and A-10C Thunderbolts that were introduced in the late 70s now reaching the end of their lifetimes, the U.S. Air Force is keen on keeping its fleet young. The F-35s that were introduced in 2016 would be a decade older by the time the A-10Cs go out, at the end of the decade, and re-engining them with advanced adaptive engines would be wise.

But with defense spending expected to stay low over the next few years,  a new engine would definitely be out of Air Force's budget.