Washington, DC, February 11 - The U.S. Air Force has begun accepting deliveries of new F-35 Lightning II fighters without installed radars, a direct consequence of persistent delays in the integration of the advanced AN/APG-85 active electronically scanned array radar. Originally planned for inclusion starting with Lot 17 aircraft in 2025, the next-generation radar, developed by Northrop Grumman, has encountered significant technical and production hurdles. These challenges stem from differences in mounting structures, power requirements, and cooling needs compared to the current AN/APG-81 radar. As a result, recent F-35 airframes configured for the APG-85 cannot accommodate the older system, forcing the program to deliver jets without any radar unit in the nose section to avoid halting production entirely.
To maintain proper weight distribution and flight balance, engineers have installed temporary nose ballast in these radar-less aircraft. This interim solution allows the jets to be ferried and potentially operated in limited capacities, though full independent combat effectiveness remains restricted without an onboard radar. The F-35s can still perform missions when flying in formation with other equipped aircraft, leveraging data links to share sensor information from APG-81-equipped companions. This approach prioritizes keeping the production line moving and delivering airframes to U.S. units amid ongoing modernization efforts under the broader Block 4 upgrade package, which relies on enhanced computing power from the Technology Refresh 3 (TR-3) configuration.
The delays highlight broader complexities in upgrading fifth-generation platforms like the F-35 Joint Strike Fighter. The APG-85 promises superior detection range, electronic warfare resistance, and integration with emerging weapons and sensors, but its development has slipped from initial timelines. Reports indicate that full operational capability for the new radar may not arrive until later production lots, potentially Lot 20 or beyond. Despite these setbacks, deliveries to international partner nations continue largely unaffected, as many of their allocated aircraft retain compatibility with the existing APG-81 radar.
These mounting issues underscore the intricate engineering and supply-chain demands of sustaining the world's largest fighter program. While the U.S. military pushes forward with acceptance of the new F-35s to bolster fleet numbers and readiness, the radar integration challenges serve as a reminder of the technical risks inherent in advancing stealth fighter capabilities. Program officials continue working with Lockheed Martin and Northrop Grumman to resolve the hurdles, ensuring the F-35 remains a cornerstone of American and allied air dominance in the coming decades.