Adaptive Engine Transition Program

Developed under the US Department of Defense’s Adaptive Versatile Engine Technology (ADVENT) and Adaptive Engine Technology Development (AETD) programs, the GE Adaptive Cycle Engine combines outstanding fuel burn with increased, fighter-level thrust, enabling next-generation military combat aircraft to go greater distances and engage more targets. Unlike traditional engines with fixed airflow, the GE ACE is a variable cycle engine that will automatically alternate between a high-thrust mode for maximum power and a high-efficiency mode for optimum fuel savings. And that means a whole new book of operational possibilities for the U.S. Air Force. The United States Air Force Life Cycle Management Center (AFLCMC), based at Wright Patterson AFB, Ohio, awarded GE Aviation a $1 billion contract June 30, 2016 to continue maturing its three-stream adaptive cycle engine via the Adaptive Engine Transition Program (AETP). AETP is scheduled to run through 2021 with extensive component, rig and engine testing.

Pratt & Whitney was selected by the U.S. Air Force Life Cycle Management Center to receive a more than $1 billion award for the Adaptive Engine Transition Program (AETP). As part of AETP, Pratt & Whitney will design, develop, fabricate, and test complete adaptive engines in the 45,000lb thrust-class, continuing the advancement and maturation of the next generation of military fighter engine technology.

Continued advances in propulsion technologies are needed to outpace ever evolving threats. AETP is specifically aimed at maturing a three-stream architecture and other advanced propulsion technologies considered essential for high-speed and long-endurance performance requirements. Pratt & Whitney is building on its position as the world's only fifth generation engine manufacturer to prepare for multiple potential low-risk follow-on Engineering, Manufacturing, and Development (EMD) program(s) for existing and next generation combat aircraft.

"We believe our program plan fully embraces the spirit and intent of the U.S. Air Force's goals to provide a highly capable adaptive engine design with the ability to power a wide range of future and legacy aircraft applications," says Dr. Jimmy Kenyon, senior director of Advanced Programs & Technology, Pratt & Whitney. "By leveraging the significant technical accomplishments achieved under the Air Force Research Laboratory's Adaptive Engine Technology Development program, as well as through the U.S. Navy's Variable Cycle Advanced Technology program, Pratt & Whitney – through AETP – will continue the progression of game-changing propulsion technologies critical to maintaining U.S. air superiority."

Pratt & Whitney demonstrated a three-stream fan in a rig in 2013 as part of the Adaptive Engine Technology Development (AETD) program. In early 2017, the company aims to take the next step and demonstrate the three-stream technology in an actual engine environment. The third stream provides an extra source of air flow to improve propulsive efficiency and lower fuel burn, or to deliver additional air flow through the core for higher thrust and cooling air.

In AETP, Pratt & Whitney will complete the detailed design optimization and conduct extensive risk-reduction and maturation activities. Studies and activities conducted as part of the program will guide the way towards using the adaptive engine in a range of future or legacy aircraft, providing confidence that it is ready for a low risk EMD effort focused on the appropriate application. From a timing standpoint, AETP will benefit fully from Pratt & Whitney's AETD and technology maturation experience, such as the demonstration of advanced turbine blade cooling technologies that allowed the company to achieve the highest-ever turbine temperature in a production-based fighter engine.

AETP technology has undergone initial development under the auspices of the Air Force Research Laboratory (AFRL) through the Adaptive Versatile Engine Technology (ADVENT) program that began in 2007 and the Adaptive Engine Technology Development (AETD) program that began in 2012.

"For nearly a decade, GE Aviation has successfully partnered with the Department of Defense (DoD) to effectively design, manufacture and test our revolutionary combination of engine architecture, compression technology, cooling technology and material technology advancements," said Dan McCormick, general manager of GE Aviation's Advanced Combat Engine programs. "We are honored to continue our work with AFRL while initiating the next phase of the technology maturation with the AFLCMC, transitioning our learnings as the only engine manufacturer to have successfully tested a full three-stream adaptive cycle engine. We will continue to work to deliver engines that meet the DoD's aggressive performance and cost targets. We believe GE is best positioned to integrate the adaptive suite of technologies into existing and next-generation combat aircraft."

GE Aviation completed its AETD Preliminary Design Review (PDR) in March 2015. This key review was held with leaders from the US Air Force, Navy and NASA following testing of the industry's first and only adaptive-cycle, three-stream engine in 2014. GE's adaptive cycle, three-stream engine extends aircraft operating range by more than 30%, improves fuel consumption by 25% and increases thrust by more than 10%. With the AETP and follow-on development programs, GE's engine could be ready to power the US military's most advanced combat jets.

Fixed cycle engines powering today's military aircraft are limited, or "fixed," to one capability: either maximum power or fuel efficiency, which restricts aircraft performance and increases sustainment costs. GE's AETP engine differs from fixed cycle engines in its ability to alter from a high-bypass, fuel-efficient engine similar to those deployed on tanker/transport aircraft to a low-bypass, high-performance engine needed for fighter jets. The adaptive feature is combined with an additional source of air, called a "third stream of cooled air," that can be used to further increase thrust, improve fuel efficiency and dramatically reduce the aircraft heat load.

After a joint GE/DoD investment of more than $1 billion in its development, GE's AETP engine is uniquely capable of meeting or exceeding DoD performance targets. It incorporates the industry's most extensive use of advanced manufacturing and heat-resistant material technologies initially developed for GE's commercial jet engines, such as ceramic matrix composites (CMC) and additively manufactured components pioneered on the best-selling LEAP and GE9X engines. These innovations--which further reduce fuel consumption and lower aircraft operating weight--enable the engine to meet or exceed the military's aggressive performance targets with field-proven, low-cost technologies.

GE Aviation, an operating unit of GE, is a world-leading provider of jet, turboshaft and turboprop engines, components and integrated systems for commercial, military, business and general aviation aircraft. GE Aviation has a global service network to support these offerings.