Lockheed Martin Aeronautical Company – Fort Worth – Chris Hanoch; Subject: PHOTO only: Denmark F-35 Delivery Ceremony_Aircraft Construction/Assembly/Flight Documentation; FP#: 20-08147; POC: Anthony Salvo; Other information: AP-1 high power engine shot in RS 13, 3-3-21, APPROVED FOR ADVERTISING BY ANGEL DELCUETO

In an unexpected event, Lockheed Martin has made public its preference for an innovative engine for the F-35, distancing itself from the Pentagon’s plan to modernize the fighter’s current powerplants, made by Pratt & Whitney. The move has drawn a vehement response from Pratt, whose surprise is evident.

Greg Ulmer, executive vice president of aeronautics, announced the news in an interview with Breaking Defense at the Paris Air Show. Ulmer stated Lockheed’s adherence to the Adaptive Engine Transition Program (AETP), specifically for the F-35  Certainly a bold step.

Advantages of the AETP Engine: A Lockheed Martin Analysis

Is Lockheed Martin utilizing a new propellant, AETP, for the F-35 ?
The XA100 is the entrant in GE Aviation’s Advanced Engine Transition Program, seen here as concept artist. New AETP engine technologies include third-stream airflow, high-temperature ceramic matrix composites, digital design, and additive manufacturing techniques. Courtesy of GE Aviation.

Lockheed Martin expounded on the virtues of an AETP engine in a statement to Defense News. They highlighted its superior power and cooling capabilities, which could push the F-35 beyond the scheduled Block 4 upgrades.

In this sense, Lockheed Martin affirmed that its AETP technologies offer greater power and better cooling, crucial to upgrade the F-35 beyond Block 4. Pratt & Whitney told Defense News that these comments “undermine” Pentagon support for the engine core upgrade.

Pratt & Whitney Position on AETP Technology

Is Lockheed Martin utilizing a new propellant, AETP, for the F-35 ?
Lockheed Martin Aeronautical Company – Fort Worth – Chris Hanoch; Subject: PHOTO only: Denmark F-35 Delivery Ceremony_Aircraft Construction/Assembly/Flight Documentation; FP#: 20-08147; POC: Anthony Salvo; Other information: AP-1 high power engine shot in RS 13, 3-3-21, 

Jill Albertelli, head of military engines at Pratt & Whitney, said that “AETP technology will lead to advanced fighter platforms” ​​but noted that Lockheed Martin’s plan to use an untested adaptive engine for a single-engine fighter could be expensive and delay the delivery of necessary capabilities to our soldiers. Albertelli argued that the Pentagon had not specified required upgrades beyond Block 4.

The F-35, a Lockheed project, aspires to continue operating for another 50 years. To maintain its effectiveness, an engine upgrade is essential. General Electric Aerospace and Pratt & Whitney are competing to develop the Advanced Engine Transition Program [AETP] engines. GE is focusing on its XA100 engine, while Pratt is on the XA101.

Implications for the defense budget

The Pentagon had to decide between the new engine and the upgrade of the existing F135 engine. In the end, they went with the cheaper option and proposed the engine core upgrade in their 2024 budget.

In a surprising twist, the House Armed Services Committee suggested an additional $588 million for the new engine in the FY24 National Defense Authorization Act while still funding the engine core upgrade.

Lockheed Martin’s change of position on the F-35’s propulsion system

In contrast to his comments in an earlier 2021 interview with Defense News, where Lockheed backed the Pentagon’s engine upgrade plan, the company now supports the new AETP engine.

According to Ulmer, this is due to the inherent benefits of the AETP, such as its superior cooling capacity and increased power, characteristics crucial to pushing the F-35 beyond the Block 4 improvements.

The F-35’s New Powerplant Could Involve Extensive Redesign

Pratt & Whitney F135 that propels the F-35- Wikipedia

However, the switch to the AETP engine would not be a straightforward process, as it could require an extensive redesign of the F-35. This would generate additional costs and possibly lead to delays in the delivery of new units.

However, Lockheed Martin believes the long-term benefits outweigh the initial challenges.

The company argues that the AETP’s superior characteristics would give the F-35 a significant strategic advantage on the battlefield.

Pentagon reaction to Lockheed Martin’s change of position

The Pentagon has yet to issue an official statement in response to Lockheed Martin’s decision. However, this action is likely to spark internal debate about the future direction of the F-35.

The Pentagon is concerned that the development and production costs of the new AETP engine could exceed its budget.

The F-35 is a crucial part of the US defense strategy. Therefore, any changes to its design, such as the transition to a new engine, will have strategic and financial implications.