The U.S. Air Force wants an innovative adaptive fighter jet engine to maintain air dominance.
Fast-tracking the fighter jet engine of the future
How Pratt & Whitney is using digital tools to speed development of its adaptive engine
With a delegation from the U.S. Air Force on hand, the demonstration of the power of digital engineering began.
A team at the RTX Technology Research Center turned on a digital model representing an architecture for an adaptive engine – one that can change on demand to deliver more speed or fuel efficiency. Hundreds of digital sensors tracked aspects of its performance.
Then, the team shut one off at random.
Normally, pinpointing which one and determining what it was measuring would have taken hours. Digital design enabled the team to do it in minutes.
The advantage to the new approach was clear.
“A lot of excitement grew from the capability of this,” said Alan Seipt, Pratt & Whitney’s validation chief for adaptive programs, “that it’s not just residing in somebody’s head or a bunch of dusty binders that you have to page through to figure out where the connections are. It’s a digital tool and with a couple buttons, you can understand where you’re at and make real decisions.”
It was one of many benefits Pratt & Whitney, an RTX business, has unlocked by designing that prototype engine, known as the XA103, in an all-digital environment. The biggest benefit, they believe, will be a fast track to an engine the Air Force needs to stay dominant.
“The United States is not interested in parity in any fights around the world,” said Alex Johnson, who leads Pratt & Whitney’s Next Generation Adaptive Propulsion, or NGAP, program. “You’re really looking to create air superiority and air dominance – and you do that by staying at least several years and preferably decades ahead of any potential adversaries.”
At a glance
Pratt & Whitney built on decades of experience to design an engine that will power future decades of military flight.
It’s the first engine the company designed in a fully digital environment from concept through manufacturing.
This digital approach will deliver groundbreaking, next-generation capabilities faster than ever.
What is a next-generation adaptive engine?
To date, military aircraft engines have been optimized according to the platform’s needs. An engine on a stealth aircraft, for example, is designed to be less observable to radar – much different from the engine on a strike fighter, whose main need is maximum thrust.
Adaptive engines turn that concept on its head. They will be able to reconfigure themselves in flight depending on the needs of the moment – switching, for example, from high thrust to high efficiency.
Here’s why that matters: It would provide stealth, power and thermal management, thrust and efficiency without sacrificing durability so the military will have more flexibility and fewer compromises when designing their mission. The Air Force is looking to the Next Generation Adaptive Propulsion engine to set the foundation for decades of military flight.
Pratt & Whitney’s proposed engine will be built to meet not only those needs, but the needs of other aircraft too.
Hear Alex Johnson describe how adaptive architectures have evolved since Pratt & Whitney used adaptive capabilities on its J58 engine designed for the record-breaking SR-71 Blackbird in the 1960s.
How digital helps meet demand
Digital design addresses communication problems that have historically hindered engine development. On a typical program, as many as 1,500 engineers would work with hundreds of vendors across dozens of software platforms and even paper documents. They had no way to combine their information into a single place where everyone could see it.
Pratt & Whitney fixed that problem through a digital collaborative environment. Engineers now have a dashboard-like interface where teams can share information and work together in real time. Their goal was to develop XA103 in a way that would reduce errors, identify problems earlier, shorten turnaround times and improve communication between internal teams, vendors and the Air Force.
The digital collaborative environment takes decades of computer-aided design work that’s been happening across the company and brings them together for greater results.
“What is happening in the digital transformation that we are going through now,” Johnson said, “is that we’re having a more concerted effort to connect some of those digital tools to have them optimize with each other.”
The team completed the program’s detailed design review in early 2025 and is now preparing to build a prototype that will continue to be tested and refined until the engine’s ground test, which is expected in the late 2020s.
The digital collaborative workspace is just one way the team is working differently. They’ve also realized time savings by bringing testing and validation earlier in the design process instead of adding test instrumentation after the engine has been designed.
Another key component of the program is its use of model-based systems, or 3D digital models that contain all the relevant program details and data. This will simplify reporting because years of test data will be neatly stored and easily accessible in the model and make it easier for onboarding teammates mid-project.
“Our current engine is over 2,000 pieces of instrumentation sensors – all with their own little story that goes along with them and why they’re needed. In the past, you’d have somebody at the center of all of that who has lived it,” Seipt said. “Now, even if a new person comes onto the program that hasn’t lived the last four or five years of history with that particular test asset, they can jump right in and have those impact analyses available immediately.”
Model-based systems will help streamline the supply chain as well. Chris Scott, from Pratt & Whitney’s supply chain team, is training roughly 200 suppliers for model-based definition for manufacturing and inspection – a method that includes manufacturing data in a 3D model rather than traditional, hard-copy blueprints. Because the models are machine readable, the supplier doesn’t have to recreate the paper blueprint with their software, which means fewer errors in translation, and they can begin working as soon as they receive the technical data package from Pratt & Whitney.
Industry studies show the time between order receipt and delivery could be cut in half when using model-based technologies.
“There’s a lot of manual handoff of information. Model-based definition for manufacturing and inspection really focuses on automating a lot of those processes,” Scott said. “We want to get away from doing data-mining activities and really focus on making decisions with relevant information in front of us in real time. There’s a lot of opportunity to speed up that process and get to market faster.”
Pratt & Whitney plans to use a digital shop floor that will automate manufacturing – as it’s already doing across several sites including Asheville, North Carolina, for airfoil production and in Oklahoma City for maintenance, repair and overhaul.
Recreating the F119 experience
The move to digital processes has made it easier for the Air Force to collaborate with Pratt & Whitney – something both parties enjoyed in the 1990s, during the development of the F119 engine for the F-22 Raptor.
“They wanted that experience again not only from the performance of the engine but from the interaction with our team,” Johnson said. “We took that to heart as we started this program, and the digital tools have given us a way to step that up.”
The digital collaborative environment allows the Air Force to access program files and provide feedback at any time through a classified system. That transparency, coupled with Pratt & Whitney’s history in military engines, has strengthened trust and shown the team’s commitment to providing new capabilities quickly.
“We’re creating perhaps the most complicated machines on the face of the planet, and yet they are some of the most reliable machines on the planet,” Johnson said. “That’s important because our team is committed to making sure the warfighter has what they need to complete their mission and come home safely. You want to make sure that it’s going to work, and you want to make sure that it’s going to get done on time – Pratt & Whitney is the place that you can get that dependable engine.”
