F-35 Alternate Engine Program: Background and Issues for Congress

Jeremiah Gertler
Specialist in Military Aviation

For four successive years, Congress has rejected administration proposals to terminate the program to develop the General Electric/Rolls-Royce F136 engine as an alternative to the Pratt & Whitney F135 engine that currently powers the F-35 Joint Strike Fighter (JSF). The administration’s FY2011 budget submission again proposes to terminate the program.

The alternate engine program began in FY1996, when defense authorization conferees directed the Department of Defense (DOD) to ensure that the JSF (then “JAST”) program “provides for adequate engine competition.” Through FY2009, Congress has provided approximately $2.5 billion for the Joint Strike Fighter alternate engine program. The program is projected to need an additional $1.9 billion-2.9 billion through 2017 to complete the development of the F136 engine.

Critics of the proposal to terminate the F136 alternate engine argue that termination was driven more by immediate budget pressures on the department than the long-term pros and cons of the F136 program. They argue that engine competition on the F-15 and F-16 programs saved money and resulted in greater reliability. Some who applaud the proposed termination say that singlesource engine production contracts have been the norm, not the exception. Long-term engine affordability, they claim, is best achieved by procuring engines through multiyear contracts from a single source.

Canceling the F136 engine poses questions on the operational risk—particularly of fleet grounding—posed by having a single engine design and supplier. Additional issues include the potential impact this termination might have on the U.S. defense industrial base and on U.S. relations with key allied countries involved in the alternate engine program. Finally, eliminating competitive market forces for DOD business worth billions of dollars may concern those seeking efficiency from DOD’s acquisition system and raises the challenge of cost control in a singlesupplier environment.

Continuing F136 development raises issues of impact on the F-35 acquisition program, including possible reduction of the numbers of F-35s that could be acquired if program funds are used for the alternate engine. It also raises issues of the outyear costs and operational concerns stemming from the requirement to support two different engines in the field. 

FY2011 defense authorization bill: In markup on May 19, 2010, the House Armed Services Committee added $485 million to continue the alternate engine program, and passed language that would limit F-35 procurement to 30 aircraft and prohibit DOD from spending 25% of its F- 35 budget until all alternate engine funds had been obligated. On May 27, 2010, the House voted to defeat an amendment that would have eliminated funding for the alternate engine.

On May 28, 2010, the White House released a statement from the President stating he “will veto any such legislation so that it can be returned to me without those provisions” if the funding for a second engine remained in the bill. The version of the authorization report reported by the Senate Armed Services Committee does not include such funding. 

FY2011 DOD appropriations bill: The Senate Appropriations Committee-reported version of the bill, released September 16, 2010, included no funding for the F-35 alternate engine.


Date of Report: September 17, 2010
Number of Pages: 63
Order Number: R41131
Price: $29.95

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