Lockheed wins $100M to fix a heat problem grounding F-35s

Every time an F-35 lands, its brakes absorb an enormous amount of heat. The world’s most advanced stealth fighter weighs more than 29,000 pounds fully loaded, lands at speeds exceeding 150 miles per hour, and stops using a braking system that has to dissipate that kinetic energy within the length of a runway. When the heat management in that system fails, the consequences ripple through the entire aircraft, degrading avionics reliability and pulling jets out of service for depot-level repairs that can take months. The Pentagon paid $100 million to get ahead of that problem.

Lockheed Martin Aeronautics, the Fort Worth-based division of Lockheed Martin that manufactures the F-35 Lightning II, received a $100 million contract order from the Naval Air Systems Command to procure 1,459 brake assembly heat sinks, the components specifically designed to absorb and dissipate the thermal energy generated during landing. Of those, 1,075 are designated for the F-35A, the conventional takeoff and landing variant operated by the U.S. Air Force and most international partners, and 384 for the F-35B, the short takeoff and vertical landing version used by the U.S. Marine Corps and several allied navies. Work will be performed in South Bend, Indiana, with completion scheduled by March 2030.

A heat sink, in this context, is a passive thermal management component, a piece of engineered material placed within the brake assembly to absorb heat that would otherwise transfer into adjacent systems. The F-35’s brake assembly sits within the landing gear structure, and the heat generated during aggressive stops or repeated landings in high-tempo operations can exceed the design tolerances of components nearby, including wiring, sensors, and avionics connections that run through the same structural areas. The contract documentation describes the effort as supporting “resolution of existing thermal management constraints” and ensuring “the reliability of critical avionics,” language that confirms the components are being procured in response to an identified and documented technical problem rather than routine inventory management.

Depot-level brake repair is among the most demanding sustainment tasks in the F-35 program. Unlike organizational-level maintenance that squadrons can perform with their own personnel and equipment, depot repair requires returning aircraft to dedicated industrial facilities where technicians with specialized tooling disassemble major systems, replace worn or damaged components, and certify the aircraft back to airworthiness standards. The F-35 program has struggled with depot capacity since the aircraft entered service, with a Government Accountability Office report in 2023 noting that the fleet’s mission-capable rate sat at approximately 55 percent, well below program targets, in part because depot repair facilities were not established fast enough to keep pace with the growing fleet. A shortage of serviceable brake components adds directly to that backlog, keeping aircraft in maintenance queues rather than in operational squadrons.

The funding structure of the contract reflects the genuinely multinational nature of the F-35 program. Of the $100 million total, $44 million comes from U.S. Air Force aircraft procurement funds, $29 million from Navy aircraft procurement funds covering Marine Corps F-35B operations, $11 million from Foreign Military Sales customers, meaning allied nations buying into the repair supply chain, and $17 million from F-35 program partner nations, the eight countries that contributed to the aircraft’s development and operate it under a cooperative agreement. The full amount was obligated at contract award, and none of it expires at the end of the current fiscal year, giving the program unusual budget stability for a multi-year parts procurement.

The 19 countries that operate the F-35, including the United States, United Kingdom, Australia, Japan, South Korea, Norway, the Netherlands, Italy, Denmark, and others, collectively fly a fleet of more than 1,100 aircraft with production ongoing. At that fleet scale, brake assembly serviceability becomes a logistics problem that compounds quickly. If each of the 1,459 heat sinks procured under this contract supports one aircraft undergoing depot brake repair, the order addresses a significant fraction of the anticipated repair demand through the end of the decade, and the contract’s 2030 completion date aligns with the program’s broader sustainment planning horizon.

The brake heat sink order also sits within the larger context of the F-35’s well-documented thermal management challenges, which extend well beyond the landing gear. The aircraft’s Power and Thermal Management System, the subsystem responsible for cooling avionics, managing heat loads from electronics, and providing environmental control to the cockpit and sensor systems, is approaching its design limits as the program pursues Block 4 and subsequent capability upgrades. Future avionics improvements, including upgraded radar and electronic warfare systems, will generate more heat than the current cooling architecture can handle, and the program office has been evaluating replacement or upgrade options for the power and thermal management system for several years. Collins Aerospace and Honeywell Aerospace are both developing competing solutions, with fielding expected no earlier than 2030 to 2032. The brake heat sink procurement addresses the immediate, fleet-wide maintenance problem while the longer-term cooling architecture challenge continues through its own program track.

For an aircraft that costs roughly $80 million per unit in the F-35A configuration and is expected to remain in service until at least 2070, keeping the brake system serviceable is not a minor logistics detail. A grounded F-35 is an expensive non-asset, and the combination of high operational tempo, the thermal stresses of short takeoff and vertical landing operations in the F-35B, and the growing number of aircraft requiring depot-cycle maintenance has created a parts demand that the program’s supply chain is being asked to meet at industrial scale. The $100 million contract is the program’s answer to that demand, placed before the shortage becomes a readiness crisis rather than after.