DAYTON, Ohio — The long run of the U.S. military’s Adaptive Engine Transition Program continues to be up within the air, but one service is attempting to fold the trouble’s technological innovations into a complicated jet’s propulsion system.
In a Tuesday roundtable with reporters in Dayton, Ohio, John Sneden, director of the Air Force’s propulsion directorate, outlined ways his organization is working to adapt AETP features into the longer term Next Generation Air Dominance platform’s engines.
That propulsion system, dubbed Next Generation Adaptive Propulsion, or NGAP, is in a preliminary design phase, Sneden said on the Air Force’s Life Cycle Industry Days event. Inside the following few years, he added, NGAP must be able to move into prototyping and testing, having learned multiple lessons from the previous work on AETP.
The Pentagon has researched adaptive engine technology through AETP since 2016 as a possible substitute for the F-35 Joint Strike Fighter’s current engine. GE Aerospace in addition to Pratt & Whitney — the latter makes the F-35′s current F135 engine — developed their very own adaptive engines and are continuing to work on NGAP.
In its March budget request, the Pentagon announced it had as an alternative decided to stick to the F135 engines and upgrade them to offer more power and cooling for the F-35. The Pentagon’s proposed budget requested no money for the choice AETP option.
But some lawmakers have since moved to revive funding for AETP so the military can proceed developing this technology to be used in advanced fighter systems.
NGAP is fully funded within the Air Force’s proposed fiscal 2024 budget, with the department requesting $595 million — a rise of $375 million over fiscal 2023.
If AETP will not be funded in FY24, Sneden said, the Air Force will shift its remaining AETP budget and activities to NGAP. Those include ongoing work developing controls for AETP’s adaptive fan, cooling technologies and advanced materials, lots of which can form crucial elements of NGAD’s eventual engine.
Sneden said AETP’s adaptive element — allowing the engine to rapidly shift to the configuration that might provide the most effective thrust and efficiency for a certain situation — and the usage of advanced composite materials, which might withstand much higher temperatures, for turbines and other components shall be central to NGAP.
But it surely’s still undecided as as to if the NGAD’s engine will use the third stream of air that’s one other a part of the AETP design, he said.
While the technology utilized in each AETP and NGAP shall be largely the identical, Sneden explained, the longer term NGAD’s engines shall be sized in a different way from those of the F-35. Which means elements of AETP would need to be resized and redesigned to be suitable for NGAD.
“We’ll have the option to port that tech over,” Sneden said. “It’s not a one-for-one; you possibly can’t just pull it off of the F-35 and move it directly over to NGAD in its current state.”
While GE Aerospace and Pratt & Whitney develop the brand new fighter’s engines, Sneden noted, the potential designers of the NGAD airframe are also working closely with them to make sure the engines will fit.
The Air Force last yr also awarded contracts price nearly $1 billion each to aircraft manufacturers Boeing, Lockheed Martin and Northrop Grumman to work on prototyping NGAD engines, although Northrop in July confirmed it might not bid as a chief contractor on NGAD. The Air Force issued a solicitation for NGAD in May, and it plans to make an award in 2024.
“We’re making one design that can … fit into any of the [airframe] designs” for NGAD, Sneden said. “In a while, as we downselect and determine who the ultimate vendor is, there could possibly be some optimization of that system and that specific design. But they’re all designing and moving across the propulsion constraints that we’ve studied and evaluated and provided to every.”
AETP testing that already occurred has been tremendously useful for NGAP, Sneden said.
“Due to the information that we’ve received off of that, we actually understand how the adaptive engine technology works,” Sneden explained. “We understand the varieties of changes that we want to make, and we will incorporate that into the baseline for NGAD.”
It would be crucial for the USA to redouble its efforts toward developing latest and progressive propulsion systems, Sneden noted. Since about 2015, China has made considerable advancements of its own on propulsion, and is beginning to catch up.
“We’re losing our propulsion result in China, which is investing heavily and developing and producing effective propulsion technologies,” Sneden said. “We have now to take care of that propulsion edge.”
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 has traveled to the Middle East to cover U.S. Air Force operations.