GE Aerospace and Pratt & Whitney — the two engine manufacturers competing to power the United States Air Force’s Boeing F-47 sixth-generation air dominance fighter — have each completed Assembly Readiness Reviews of their respective adaptive-cycle turbofan designs within days of each other in the second week of May 2026, representing the most substantive public disclosure of parallel programme progress since both companies received up-to-$3.5 billion contracts under the Next Generation Adaptive Propulsion (NGAP) programme in January 2025.
GE Aerospace confirmed on May 11, 2026, that it had completed an Assembly Readiness Review of its XA102 adaptive-cycle engine. Pratt & Whitney, on the other hand, had already announced completion of its own equivalent review — a fully digital Assembly Readiness Review of its XA103 engine — on May 8, 2026.
GE Aerospace XA102: Assembly Readiness Review Cleared on May 11
GE Aerospace completed the Detailed Design Review (DDR) of the XA102 in February 2025, at which point it presented a comprehensive digital engine model to the U.S. Air Force and validated its readiness for full-scale demonstrator build. Following the DDR, GE Aerospace was awarded the next contract phase to procure, assemble and test an XA102 full-scale demonstrator engine.
The Assembly Readiness Review completed on May 11 now clears the engine for the build phase, signifying that the assessment addressed not only the design maturity of the XA102 itself, but also the manufacturing process infrastructure and supply chain architecture that will support physical production of the demonstrator.
Aviation Week reported that the review’s scope encompassed this broader industrial readiness dimension. GE says it expects the U.S. Air Force to award funding for the next phase of NGAP development later this year. Commenting on the milestone, Dr. Steve “Doogie” Russell, Vice President and General Manager of GE Aerospace’s Edison Works advanced projects unit, stated:
“With the completion of the Assembly Readiness Review, we are demonstrating the maturity of our XA102 engine design and the strength of our digital-first approach to developing next-generation propulsion systems.”
A defining feature of the XA102’s development trajectory is that it is the first engine in GE Aerospace’s history to be designed entirely using model-based systems engineering (MBSE), which is a digital-first methodology where a comprehensive virtual model of the engine serves as the authoritative source of design truth for all engineering disciplines, supply chain partners, and test planning activities.
GE Aerospace’s official press release emphasised that this approach delivers “improved range, survivability and thermal management capabilities for advanced weapons and sensors.” The XA102 builds upon the prior-generation XA100, which completed multiple successful rounds of testing under the AETP and whose accumulated data provided a validated technological foundation for the sixth-generation design.
Pratt & Whitney XA103: A Fully Digital Review and the Transition to Physical Hardware
Three days before GE’s May 11 announcement, Pratt & Whitney published its own milestone on May 8, 2026, through an RTX press release: the completion of a fully digital Assembly Readiness Review for its XA103 engine — the first fully digital technical assessment of its kind for a programme of this classification and scale.
The milestone marks Pratt & Whitney’s transition from designing the XA103 in a digital environment to procuring and producing physical hardware from its supply network. Unlike a conventional review process, the XA103’s Assembly Readiness Review was conducted entirely through digital models — an approach the company describes as not merely a process efficiency, but as the validation of a new paradigm for military propulsion development.
Pratt & Whitney’s official RTX press release quoted Jill Albertelli, President of Pratt & Whitney’s Military Engines business, as stating:
“This milestone demonstrates Pratt & Whitney’s investment in digital infrastructure, showcasing seamlessly integrated digital capabilities and reinforcing our strong collaboration with the U.S. Air Force. As we move forward with assembling our engine for testing, our NGAP team is simultaneously developing novel digital validation tools. The performance we expect this engine to deliver exceeds anything available today, reinforcing the critical importance of continuous improvement and stable investment in maintaining propulsion as a strategic competitive advantage.”
Albertelli had previously, at the DDR stage in February 2025, described the significance of the digital methodology itself, saying: “The significance of this first fully digital review cannot be understated. Digital processes throughout the lifecycle are crucial to rapidly and efficiently deliver advanced warfighter capabilities.”
The XA103 draws on Pratt & Whitney’s accumulated experience from nearly two million flight hours on the F119 and F135 — a data foundation that the company says directly informs the sixth-generation design’s adaptive architecture and reliability targets.
Aerospace Global News reported that the XA103’s model-based digital design environment has already halved the pace at which it delivers technical data packages, by distributing advanced digital models to suppliers and engineers — enabling rapid design iteration, easier system integration, better forecasting for manufacturing resources, and faster model testing.
The engine is described by Pratt & Whitney as “platform-agnostic” meaning its adaptive architecture is designed for applicability across multiple future combat aircraft types, not solely the F-47. Testing of the assembled XA103 is expected in the late 2020s.
