The F-35 Lightning II fighter jet is the most expensive fighter procurement program in modern history.
Pratt & Whitney, the engine manufacturer for the F-35 Lightning II stealth fighter jet, recently received $3 billion to build hundreds of new engines for the aircraft.
According to the contract, released on the Department of Defense’s webpage on August 22, the engine manufacturer was awarded roughly $2.9 billion for the production of 141 new F135 engines, as well as spare parts and ongoing maintenance support—specifically for the “Lot 18” batch of incoming F-35s.
Lockheed Martin, the manufacturer of the F-35’s airframe, received its Lot 18 contract back in December. That contract is altogether worth almost $12 billion, covers 145 airframes, and is due by mid-2027.
The engines within the new contract are intended for both the US military and its international partners in the F-35 Joint Strike Fighter program. As of August 2025, the F-35 program has 19 international partners from across the world, including the United Kingdom, Japan, Germany, Israel, Australia, Greece, and Singapore.
“This modification adds scope for the production and delivery of 141 F135 propulsion systems in support of Lot 18 F-35 aircraft production for the Joint Strike Fighter program for the Air Force, Marine Corps, Navy, F-35 Cooperative Program Partners, and Foreign Military Sales (FMS) customers,” the Department of Defense stated in the awarded contract.
The Pentagon expects the program to be completed by February 2028. Moreover, the US military plans to have more than 600 operational F-35s in service across all service branches by 2029. In a potential near-peer conflict with China or Russia, the US military would rely heavily on the aircraft’s advanced capabilities to achieve air superiority and success on the ground or sea.
The F-35 is a single-engine aircraft. However, its engine is special because it has to accommodate three different versions of the same aircraft—the “A,” “B,” and “C” variants, each of which has its own unique needs. It is not practical to build three different engines for each variant, but this means that one engine must be capable of a range of different functions—most notably including VTOL capabilities for the F-35B, the Marine Corps’ F-35 variant.
Of the $2.9 billion, the US Navy will pay approximately $656 million over two fiscal years (Fiscal Years 2024 and 2025). During the same period, the US Air Force will pay around $615 million, international partners will pay roughly $514 million, and non-US Department of Defense participants will pay $228.5 million.
The F-35 Lightning II fighter jet is the most expensive fighter procurement program in modern history. According to the Government Accountability Office (GAO), the cost of the F-35 for the US military will exceed $2 trillion over the span of its service life. Although that is an undeniably high sum, the F-35 Joint Strike Fighter program essentially produces three different aircraft in a similar platform and with closely related capabilities.
About the Author: Stavros Atlamazoglou
Stavros Atlamazoglou is a seasoned defense journalist specializing in special operations and a Hellenic Army veteran (national service with the 575th Marine Battalion and Army HQ). He holds a BA from the Johns Hopkins University and an MA from the Johns Hopkins’ School of Advanced International Studies (SAIS). His work has been featured in Business Insider, Sandboxx, and SOFREP.
Image: Wikimedia Commons.
