WASHINGTON — The Defense Department awarded Pratt & Whitney a bridge contract worth nearly $4.4 billion to provide at least 250 engines for the F-35 fighter.

The contract modification from the F-35 Joint Program Office will cover production of the 15th and 16th lots of the F135 engine used in all three variants of the F-35.

The Pentagon said Wednesday that 178 of the engines that will be produced under this contract will go to U.S. F-35s. Pratt & Whitney said the remaining engines will go to the forces of allied nations that also fly the aircraft.

If all options in the contract are exercised, Pratt & Whitney said it could cover as many as 518 engines at a total value of about $8 billion.

This deal is intended to keep F135 engines in production while Pratt & Whitney and the F-35 JPO finalize a formal production contract for lots 15 through 17, for which they reached an agreement in principle in April.

Pratt & Whitney expects to start delivering these engines this year, and continue through the end of 2025.

Most of the F-135-PW-100 engines, 108 of them, will go to the Air Force’s F-35As. Another 29 will go to the Navy, and 15 will go to the Marine Corps. The contract also provides for 26 F-135-PW-600 engines for the Marines, which power the vertical take-off-and-landing F-35B variant flown by that service.

The deal would also provide a Block 4 STOVL developmental engine for flight tests.

The contract covers long lead time components, parts and materials needed to keep those engines in production for foreign customers, as well as spare engines, power modules, and other hardware.

The work will be carried out at locations including sites in Connecticut where Pratt & Whitney is headquartered.

Stephen Losey is the air warfare reporter for Defense News. He previously covered leadership and personnel issues at Air Force Times, and the Pentagon, special operations and air warfare at Military.com. He has traveled to the Middle East to cover U.S. Air Force operations.

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