Pictured is a U.S. Air Force photo of an F-35A with the 356th Expeditionary Fighter Squadron, as the aircraft lands at Kadena Air Base Japan on March 30.
The Air Force’s fiscal 2027 future years defense plan (FYDP) contains more than $1.7 billion to retrofit 181 Lockheed Martin F-35As in Lot 17 and prior with the future Northrop Grumman AN/APG-85 radar.
The service has fielded 541 F-35As, and Lot 17 deliveries began last year.
The FYDP has $133 million targeted in fiscal 2031 for retrofitting 14 F-35As with APG-85s–a unit cost of $9.5 million per radar, and outside the FYDP the service said it plans to spend about $1.6 billion to retrofit another 167 jets with the APG-85.
The F-35 currently carries the AN/APG-81 radar, also by Northrop Grumman.
Radar mountings in the F-35’s nose are different for the APG-81 and the APG-85 radar–a difference which has helped complicate fielding of the new radar which was to deliver with F-35 Lot 17.
The Air Force has been considering a dual-mount bulkhead, though the latter may take two years to field.
Sources have said that the Air Force is able to fly the planes with ballast in the nose, as long as they are accompanied by and data linked to other F-35As with the older APG-81.
In a wartime setting, that would mean all four F-35As in a formation–each dozens of miles apart–would fire on targets picked up by the plane with the radar. Yet, that type of operation is problematic, even given the F-35’s sensor fusion, as a one-radar formation could increase the “ghosting” phenomenon in which the aircraft’s displays sometimes show multiple tracks for the same target aircraft, depending on inputs from different sensors on the F-35.
Radar-less F-35s “can participate in training missions and there will be moderate degradation to blue desired learning objectives and significant degradation to blue training,” one fighter pilot told sister publication Defense Daily. “I don’t know if they’re programming some sort of radar surrogate trainer into the software to enable pilots to train despite the lack of hardware since the radar is a tool that the pilots need to learn and practice using.”
“Blue training” refers to that for friendly forces in exercises against adversary “red air.”
Radar-less F-35s would have “huge implications for the fighting capability of the force as I would assess 100 percent of those jets as non-deployable,” the pilot said. “I suppose in the end if we need to, we’ll lower the standard to accommodate them, but it would require a significant number of combat losses before we’re willing to do that, as the radar is not just important for offensive/defensive capabilities, but also for safety of flight.”
The fiscal 2025 Air Force budget request had said that full procurement funding would begin in fiscal 2027 with Lot 21 for the first APG-85 to field on an F-35A by January 2029.
Yet, amid attention brought by Rep. Rob Wittman (R-Va.) to the APG-85 fielding delay, the Air Force now expects to receive the first APG-85 in April 2028–nine months earlier than previously scheduled. Wittman chairs the House Armed Services Committee’s tactical air and land forces panel.
The unit cost of the APG-85, including two years of advance procurement funding, is about $8.8 million for production line F-35As, according to the fiscal 2027 Air Force procurement budget, which lays out a nearly $335 million request for 38 radars. The latter APG-85s are not covered under the existing F-35 contract with Lockheed Martin but instead go to the military as government furnished equipment. An APG-85 procurement contract may come this November.
The APG-85, which thus far is only for U.S. F-35s, is to deny adversary use of the electromagnetic spectrum and to allow better weapons accuracy and targeting of enemy airborne and surface radars at greater ranges than the fighter’s current APG-81.
“Retrofit radars will be used to replace APG-81 radars on existing aircraft, i.e., Lot 17 and prior,” the Air Force said on Wednesday in response to email questions. “Air Combat Command is formulating a retrofit plan for all aircraft modifications including the APG-85. The additional cost of the retrofit radars includes work, tooling, and parts needed to remove the APG-81 radar and conduct other modifications to the airframe needed to receive the APG-85. Removing the APG-81 and conducting airframe modifications is not needed for production line aircraft, therefore the lower cost.”
A version of this story originally appeared in sister publication Defense Daily.
