Pratt & Whitney and General Electric have completed an assembly readiness review of the XA103 and XA102 engines, activating the supply chain to prepare for physical NGAP engine assembly.
Engine manufacturers Pratt & Whitney (P&W) and GE Aerospace have completed assembly readiness reviews (ARR) for the XA103 and XA102 adaptive cycle engines, both companies announced in the past few days. The engine, which P&W defines as platform agnostic, is being developed as part of Next Generation Adaptive Propulsion (NGAP) to power future U.S. Air Force aircraft, including the F-47 Next Generation Air Superiority (NGAD) fighter.
The companies said they are now transitioning from testing digital engine models and simulations to procuring components from other suppliers to assemble physical engines for testing. There is no timeline yet, but P&W said it expects testing to take place in the late 2020s.
XA102 and XA103 passed Critical Design Review (CDR) in 2023 and 2024, respectively. The companies then completed a detailed design review (DDR) for the engine in early 2025 and awarded a $3.5 billion U.S. Department of War (DoW) contract to P&W and GE Aerospace to develop the prototype.
Ground and flight tests are expected to follow over the next few years. However, the engines may not be ready in time for the F-47’s proposed first flight until 2029, with the first batch of aircraft reportedly using a different powerplant instead of the NGAP engines. flights global.
The Air Force’s fiscal year 2027 budget seeks $514 million for NGAP, a $187 million increase from the previous year, specifically to fund competitive prototyping. The service also seeks $5 billion in research, development, test, and evaluation (RDT&E) funding for the F-47 NGAD in FY2027, peaking at $5.25 billion in 2028, before declining to $4.12 billion in 2029, $3.29 billion in 2030, and $2.95 billion in 2031.
ICYMI: Pratt & Whitney releases images of NGAP products cut from metal and designed digitally. @usairforce – XA103 engine.
For more information, see: @AviationWeek: https://t.co/glZI2zNvXc pic.twitter.com/8t1f98pdq1
— RTX (@RTX_News) July 11, 2025
NGAD’s renderings also appeared in P&W’s promotional videos in June 2025 and February 2026. However, this is only a concept and far from an actual aircraft whose appearance is still kept secret.
P&W XA103
Pratt & Whitney, an RTX company, said in a May 8 announcement that it has completed a full digital technical evaluation of the XA103 engine for the U.S. Air Force’s Next Generation Adaptive Propulsion (NGAP) program. “The assembly readiness review represents Pratt & Whitney’s progress in transitioning from designing in a digital environment to procuring and producing physical hardware,” the company explained.
“This milestone demonstrates (the company’s) investment in digital infrastructure, showcases seamlessly integrated digital capabilities, and reinforces our strong collaboration with the U.S. Air Force,” said Jill Albertelli, president of P&W’s Engine Division. The next step will be for Pratt & Whitney’s NGAP team to “work with our supply base to procure the components needed to assemble XA103 for testing,” which is expected in the late 2020s.
“As we proceed with assembling the engine for testing, the NGAP team is simultaneously developing new digital verification tools,” Albertelli added. “The performance we expect this engine to deliver surpasses anything currently available, further emphasizing the importance of continuous improvement and stable investment in maintaining momentum as a strategic competitive advantage.”
The XA103 engine’s adaptive cycle design “provides improved survivability, fuel efficiency, and robust power and thermal management capabilities for next-generation platforms.” Adaptive cycle engines can adjust their bypass ratio (the ratio between cool air flowing around the engine core and air entering the core for combustion) in flight.
This allows the engine to switch between high and low bypass modes. This allows the aircraft to switch between long-range, fuel-efficient and high-performance flights with increased speed, thrust and power generation modes depending on mission needs.
GE XA102
GE Aerospace said the assembly readiness review (ARR) for the XA102 adaptive cycle engine follows a rigorous digital model-based systems engineering design and is paving the way for decisions on industrial and commercial aspects ahead of contract award for the next phase of the NGAP. “ARR validates that the XA102 engine design, manufacturing process and supply chain are progressing and the next phase of the order will be awarded later this year,” the company says.
GE said, “The comprehensive digital engine model (…) utilizes a model-based definition approach instead of traditional two-dimensional drawings.” The first phase of the program will conclude once all demonstrations of the model-based engine have been completed, the company added.
A digital twin-based model-based systems engineering (MBSE) development approach for building airborne platforms such as the B-21 Raider and NGAD allows near-accurate simulations of aircraft performance to test exact replicas. This allows changes and modifications to be incorporated quickly without delaying production and delivery schedules.
GE also mentioned the earlier XA100 engine, which was developed for a potential F-35 re-engine and for which the XA102 was designed. The engine “has matured adaptive engine technology after several successful tests.” This informed a digital model that “improves accuracy and accelerates production schedules.”
“The completion of the assembly readiness review demonstrates the maturity of the XA102 engine design and the strength of our digital-first approach to developing next-generation propulsion systems,” said Dr. Steve “Doogie” Russell, vice president and general manager of GE Aerospace’s Edison Works. “Using a fully integrated digital engine model encompassing design, manufacturing and inspection allows us to deliver advanced capabilities to the warfighter faster and with greater precision.”
Like P&W, the company did not explicitly mention the F-47 and only vaguely hinted at the future fighter’s expected capabilities. “These technologies will enable next-generation fighters with improved range, survivability and thermal management capabilities for advanced weapons and sensors,” the company said.
