Mystery foreign buyer pays for its own custom F-35

An unnamed foreign government is paying Lockheed Martin another $18.8 million to develop and integrate a version of the F-35 fighter jet built to its own specifications, the U.S. Department of War said on Oct. 15. The Pentagon’s daily contract announcement said the modification to an existing contract with Lockheed Martin Aeronautics in Fort Worth, Texas, adds scope for system development, demonstration and integration work on an F-35 variant tailored to the requirements of an unspecified Foreign Military Sales customer. The customer is covering the full $18.8 million, which was obligated when the contract was signed. Foreign Military Sales is the government-to-government route Washington uses to sell weapons abroad, and Pentagon contract notices sometimes leave the buyer unnamed when the customer’s identity is considered sensitive. About 80% of the work will take place in Fort Worth, where Lockheed builds the F-35, and the remaining 20% at undisclosed locations in the continental United States. The work is scheduled to run through December 2030, and Naval Air Systems Command at Patuxent River, Maryland, which handles F-35 contracting, awarded the sole-source deal. The award is the latest step in a long-running effort on the same contract. The U.S. Navy awarded Lockheed a $53.4 million modification in August 2022 for continued engineering on the design and development of a Joint Strike Fighter variant tailored for an unspecified FMS customer, followed by a $12.9 million modification in August 2025, according to federal contracting records. The new action, numbered P00011, now combines cost-plus-incentive-fee and firm-fixed-price terms. The F-35 comes in three versions: the conventional-takeoff F-35A, the short-takeoff and vertical-landing F-35B, and the carrier-based F-35C. Lockheed has delivered jets to more than a dozen foreign air forces, and some customers integrate national weapons, communications or electronic warfare gear on their aircraft. Israel’s F-35I Adir is the best-known example of a country-specific version, carrying Israeli-developed systems on the F-35A airframe. When a similar tailored-variant contract surfaced in 2021, aviation analysts speculated about which country was behind it, with Key Aero pointing to customers such as Singapore that were then taking first deliveries. The Pentagon has never publicly named the customer under this contract. The latest award comes as F-35 production remains near record levels. Lockheed delivered 191 F-35s in 2025, and recent long-lead contracts for Lots 20 and 21 cover nearly 200 more jets for U.S. services, partner nations and foreign buyers. Work on the tailored variant under the new modification is set to continue for more than four years, through December 2030.