P&W and GE successfully passed the Detailed Design Review of their offerings for the U.S. Air Force’s next generation NGAP engine, expected to power the NGAD manned fighter.
Pratt & Whitney and General Electric Aerospace have announced the successful completion of the Detailed Design Review (DDR) of their offerings for the U.S. Air Force’s Next Generation Adaptive Propulsion program, the next generation engine which is supposed to be used for the Next Generation Air Dominance aircraft.
The announcement follows the recent news about the Air Force deciding to accelerate the development of the engines with the upgrade of the contracts originally awarded to both companies in 2022. P&W and GE previously completed another key design review in February 2024 and December 2023, respectively.
Pratt & Whitney’s XA103 engine
Pratt & Whitney, which is now part of RTX, announced on Feb. 20, 2025, the completion of the Detailed Design Review (DDR) of the XA103 engine, its pitch for NGAP. Interestingly, the company noted that it presented its work “directly from its collaborative digital environment, providing reviewers with immediate access to all the data and material to satisfy the stringent criteria.”
“The significance of this first fully digital review cannot be understated,” said Jill Albertelli, president of Pratt & Whitney’s Military Engines business. “Digital processes throughout the lifecycle are crucial to rapidly and efficiently deliver advanced warfighter capabilities. As we celebrate our centennial, the digital tools and processes that our NGAP team has demonstrated, and will continue to advance, will be at the foundation of our technology maturation for our future next-gen solutions.”
Now that the DDR is complete, the company said that the development team can begin procuring hardware for the construction of the XA103 prototype ground demonstrator. The testing of the engine demonstrator is expected in the late 2020s.
“For decades, propulsion has been a key differentiator for the United States, and we are working with the U.S. Air Force to make sure it stays that way,” said Chris Flynn, vice president of Military Development Programs at Pratt & Whitney. “Collaborating with the U.S. Air Force, we have supported every generation of jet engine development since World War II. XA103, our adaptive engine for the future, will continue to advance our digital and agile design and development capabilities while advancing the propulsion capability for the warfighter.”
In the press statement, Pratt & Whitney described its proposed design for the NGAP engine saying it has an adaptive architecture which enables its components to actively adjust for optimized fuel efficiency, survivability, and power and thermal management. Previously, the company said these are key to enabling future air dominance capabilities, such as the required range, weapon and sensor capability, and persistence that platforms will require to meet evolving operational needs.
The technologies and architectures of the NGAP program are being informed by the U.S. Air Force previous investment in the Adaptive Engine Transition Program, whose learnings are considered invaluable as some of the technologies could be “portable” between the two programs. In the end, the goal of the NGAP engine is to surpass the capabilities of fourth- and fifth-generation engines, says the company.
General Electric Aerospace’s XA102 engine
Just a day earlier, on Feb. 19, 2025, General Electric Aerospace announced the successful completion of the Detailed Design Review (DDR) for its XA102 adaptive cycle engine. The company says the review validated the readiness of the digital engine model for the next phase of development.
Notably, the press statement mentioned that the XA102 is the first engine in GE Aerospace’s history to be developed using model-based systems engineering (MBSE), which represents a transformative shift in how advanced propulsion systems are designed and tested. MBSE is a relatively new methodology which uses digital modeling and simulation to support the entire lifecycle of a system, from conception and design to verification and validation activities, through to decommissioning.
MBSE is considered more efficient than traditional methods, and it helps in identifying and resolving problems even before physical prototypes are built. Also, it allows to reduce the risk of errors thanks to the visual and interactive nature of models which improve communication and decision-making among engineering teams, while also allowing greater traceability, complexity, accuracy and speed.
“GE Aerospace is making great strides with model-based engineering, which has been instrumental in the success of the XA102 engine design,” said Dr. Steve “Doogie” Russell, vice president and general manager of Edison Works at GE Aerospace. “As we transition into the procurement and build phase, we will continue to incorporate this innovative approach while working closely with our supply chain partners to advance the engine toward a full-scale demonstration.”
Similarly to P&W, after the completion of the DDR, GE Aerospace has been awarded the next contract phase to procure, assemble and test a XA102 full scale demonstrator engine. Interestingly, the mention of the contract immediately links the DDR to the recent increase in the funding for the NGAP contracts.
In fact, the contracts’ notices mentioned that “the work includes design, analysis, rig testing, prototype engine build and testing, and weapon system integration.” This could possibly imply that the DDR was one of the conditions which were met before the new contracts were awarded.
Among the critical aspects of its adaptive cycle engine, the company says it will provide greater range and significantly more thermal management capability compared to today’s most advanced combat engine. While GE did not disclose a timeline, the testing of the XA102 should be expected by the late 2020s, similarly to P&W.
Next Generation Adaptive Propulsion
Both General Electric and Pratt & Whitney previously designed engines for the Air Force’s Adaptive Engine Transition Program (AETP), researching potential options for replacing the engines of the F-35 fleet with an improved and more fuel-efficient adaptive cycle engine. However, in 2023 the service decidedd to cancel the program and instead upgrade the existing Pratt & Whitney F135 engine.
GE’s XA100 and P&W’s XA101, developed for AETP, became the foundation of the improved XA102 and XA103 offerings for the NGAP program. As adaptive cycle engines, these are expected to be able to adjust in flight, providing either more power or operating in a more fuel-efficient, according to the situation.
General Electric previously stated that the XA100 engine was around 25% more efficient than the existing F135 powerplant, while also offering between 10% and 20% more thrust. According to officials, the adaptive cycle engine technologies developed under the AETP and NGAP programs could herald a “revolutionary leap” in airplane propulsion.
Both companies are now moving towards the manufacturing full scale engine demonstrators and testing, but current plans for NGAP foresee eventually eliminating one of the two suppliers from the program. However, the future of NGAD, which is expected to use these engines, is still uncertain, adding some uncertainty also to NGAP.
In fact, the future of the NGAD sixth-generation aircraft is suspended and awaiting a decision by the new Trump administration. The program underwent an extensive review in 2024, with the objective of reassessing the requirements for the 6th generation fighter and explore whether the development strategy aligns with the evolving threat landscape and budget realities. While the Air Force appeared to back the manned 6th gen fighter, the final decision is in the hands of the government.
