In accordance with reviews, U.S. F-35 may need been delivered since June 2025 with a ballast rather than the brand new APG-85 radar which has been affected by delays.
Latest reviews point out that a variety of newly delivered F-35 Lightning II plane could also be getting into service and not using a absolutely put in onboard radar. The problem, first reported final week by Protection Each day and affiliate publication Avionics Worldwide, reportedly impacts F-35s delivered to the U.S. army since June 2025.
These plane have been deliberate to obtain the brand new APG-85 radar, developed to exchange the present APG-81 radar on F-35s in Block 4 configuration beginning with Manufacturing Lot 17. Nonetheless, the brand new radar is being affected by delays and has reportedly but to enter the manufacturing stage.
The event of the APG-85 was first publicly acknowledged by the F-35 Joint Program Workplace (JPO) in 2023, adopted few days later by Northrop Grumman’s announcement. The corporate additionally manufactures the present APG-81.
Official Statements
As the unique reviews quoted an unnamed supply, we reached out to the F-35 JPO, Lockheed Martin, Northrop Grumman and the U.S. Air Power. Whereas the latter two didn’t return our request for a press release on the time of writing, Lockheed Martin referred us to the JPO.
In an emailed assertion, an F-35 JPO spokesperson instructed us:
F-35 Lightning II plane are being constructed to accommodate the F-35 superior radar (APG-85) for U.S. Air Power, Navy, and Marine Corps. Preliminary fielding for some F-35 plane is deliberate for Lot 17, which started supply in 2025 and continues via September 2026.
Because of program safety causes, we’re defending any extra info with enhanced safety measures.
As a matter of truth, the assertion neither confirms nor denies the reviews concerning the radar-less F-35s. Whereas no official affirmation has been issued to the general public, Congress is already knowledgeable concerning the concern.
Rep. Rob Wittman (R-Va.). Vice Chairman of the Home Armed Companies Committee and Chairman of the Tactical Air and Land Forces Subcommittee was just lately requested concerning the reviews, to which he replied “I do know all about it, however the supply of the plane is assessed,” including he “can’t communicate to the situation of the plane.”
Nonetheless, he additionally commented concerning the integration of the brand new radar, which he outlined as “difficult.”
“The APG-81 is completely different than the APG-85, and subsequently delivering the plane, as presently configured, with an APG-85 radar versus an APG-81 radar is difficult,” stated Wittman. “The bulkhead configuration is essential as a result of for each of the radars, they’re very completely different.”
The congressman praised the capabilities of the APG-85, explaining that the radar is among the many causes for the upgrades to the engine. As we beforehand reported right here at The Aviationist, Pratt & Whitney is engaged on the F135 Engine Core Improve (ECU), designed to reinforce thermal administration and auxiliary energy technology to fulfill the rising calls for of the F-35’s onboard programs.
“It’s an extremely superior radar,” Wittman stated. “The arrays on it give it rather more energy which is why we’ve got to improve the engine. I believe we’d like about 82 kilowatts of energy versus what it’s producing proper now. The APG-85 is essential to Block 4, and it’s key to TR-3 software program improve capabilities and integration with the imaging system, the Distributed Aperture System.”
Measures are being taken to speed up supply. Wittman stated steps taken up to now “condensed the testing regime,” whereas work is being achieved to “proceed to compress the schedule” much more.
“I spoke to Lockheed […], they usually’re working with Northrop to get APG-85 delivered even sooner,” Wittman stated. “It’s my hope they do it as quick as humanly attainable and have the system carry out. I don’t need it delivered, if it’s gonna be operationally poor as a result of then the plane sits on the tarmac.”
Radar-less F-35s
In accordance with the unnamed supply, the difficulty solely affected F-35s delivered to the U.S. army, as they’re presently the one ones slated to obtain the brand new radar. Even with out the radar, the plane are nonetheless airworthy, though they required a ballast within the nostril to keep away from affecting the steadiness whereas in flight.
It should be famous that the difficulty, whereas its severity shouldn’t be negligible, it isn’t unprecedented. The truth is, within the Nineteen Eighties, the Royal Air Power’s Twister F.2 was initially delivered with out the Foxhunter radar on account of delays, changed by a concrete ballast for steadiness.
An apparent query could be why, given the delays with the APG-85, the F-35s weren’t delivered with the APG-81 as interim answer. This isn’t attainable due to the completely different bulkhead configuration, which makes the 2 radars not interchangeable.
One of many causes is expounded to the truth that the bulkhead can be used to appropriately place the radar so the array may be within the appropriate perspective. Having to make use of a special perspective would significantly have an effect on the efficiency of the radar.
In accordance with Breaking Protection, Lockheed Martin’s CEO Jim Taiclet already warned in 2025 about attainable dangers within the radar’s supply schedule. An answer to mitigate these dangers has additionally been proposed, though it could take presumably two years to ship.
The truth is, Taiclet wrote in an unclassified letter to then Air Power Chief of Employees Gen. David Allvin that, as a part of “proactive steps to create viable choices,” the corporate already began designing a brand new bulkhead that “helps a choice level to find out which radar system to incorporate in U.S. Lot 20 manufacturing plane deliveries.”
This could imply that, counting all U.S. plane in Heaps 17, 18 and 19, as much as 229 plane may be affected by the delays within the radar supply. Nonetheless, if solely the F-35As have been to be affected – because the preliminary report particularly talked about the A variant when asking Wittman for remark – that quantity would lower to 131 airframes.
Ballast’s Picture
Instantly after the primary reviews concerning the radar concern got here out, a photograph went viral, displaying one of many presumed radar-less F-35s with the nostril cone eliminated and the ballast put in. Nonetheless, that picture is totally unrelated and dated to even earlier than the delays of the APG-85 grew to become recognized.
The truth is, the picture was captured at Hill Air Power Base, Utah, on Sept. 17, 2024, throughout a joint coaching train on crash, broken, disabled plane restoration (CDDAR) procedures. Furthermore, the F-35A within the photograph is partially disassembled, with extra than simply the nosecone lacking, to not point out the emergency providers Marines that may be seen within the foreground.
Including to the incongruencies, the ballast seen put in on that F-35A seems to be made of 4 health club weight plates, presumably the 45 lb (20.4 kg) plates that may be generally present in U.S. gyms. Whereas such a ballast would work on the bottom and preserves the airframe’s steadiness, it’s unlikely for use in flight operations, with presumably a extra particular answer getting used.
Transition to APG-85 and Tech Refresh 3/Block 4
You will need to notice that the APG-85 is among the predominant parts of the Expertise Refresh 3 (TR-3) and the related Block 4 configuration. Points with the brand new configuration prompted a halt to the deliveries in July 2023.
A yr later, in July 2024, the F-35 JPO and Lockheed Martin agreed on a “truncated” model of the brand new configuration as stopgap, permitting to renew deliveries. Particulars concerning the truncated TR-3 weren’t launched, however this allowed to lastly clear the backlog in Might 2025.
A complete of 72 jets piled up at Lockheed Martin’s plant in Fort Value, Texas, a lower within the preliminary estimates that forecasted as much as 120 F-35s that could possibly be undelivered. The clearing of the backlog additionally contributed to the corporate setting a report delivering 191 F-35s in 2025.
With these plane being a part of the sooner Lot 16, they’d not be affected by the radar drawback as they’d come out of the manufacturing line with the APG-81. It’s unclear if the choice to put in a ballast as a substitute of the APG-85, if confirmed, was a part of measures being taken to keep away from having F-35s piling up once more till the ship of the brand new radars.
The Expertise Refresh 3 (TR-3) has been outlined because the “spine” for the upcoming Block 4 improve. The Block 4 contains {hardware} upgrades to 75 main programs, with enhancements to the digital warfare suite, the brand new APG-85 radar, EOTS (Electro-Optical Monitoring System), improved cockpit shows, navigation and communication programs and a next-generation Distributed Aperture System (DAS).
This system skilled extreme points which significantly impacted the fielding schedule of the brand new configuration. In accordance with the Authorities Accountability Workplace (GAO), the problems have been primarily attributed to software program that would not help the F-35’s radar and digital warfare programs as supposed.
“Program officers acknowledged that early variations of radar and in-flight programs software program can generally expertise rebooting points,” the GAO stated. “Nonetheless, even after being practically a yr delayed, TR-3 software program continues to be unstable, in line with check officers.”
The interim “truncated” TR-3 affords a few of the deliberate capabilities whereas the rest of the issues is being solved. The whole TR-3 is deliberate to be later retrofitted on delivered plane, with the retrofit requiring 14 days of downtime and carried out throughout scheduled upkeep, as we beforehand reported right here at The Aviationist.
APG-85
As we talked about in our earlier reviews, the point out of the APG-85 first appeared within the U.S. Air Power’s unfunded want record for Fiscal 12 months 2023, which included seven F-35A in Block 4 configuration with the APG-85 radar as a part of the Lot 17. The APG-85 designation emerged once more few months later, with the F-35 JPO later confirming that certainly a brand new radar was within the works.
“The U.S. Air Power, Navy, and Marine Corps are collectively creating and integrating a complicated radar for the F-35 Lightning II, which is able to defeating present and projected adversarial air and floor threats,” stated the F-35 JPO. “This superior radar will probably be appropriate with all variants of the F-35 plane.”
With out realizing the rest, the APG-85 may be a closely modified APG-81, to such extent that it required a brand new designation, or a very new radar being developed. The truth is, if that was simply an improve, the designation would have been APG-81v1, as achieved for different radars.
The event of the APG-81 formally began in 2001, though it traced its roots to the Nineteen Nineties. Described because the successor of the F-22’s APG-77, the radar relies on Gallium Arsenide (GaAs) Energetic Electronically Scanned Array (AESA), with air-to-air and air-to-ground modes, excessive decision Artificial Aperture Radar (SAR) mapping, Floor Transferring Goal Indication (GMTI) and Digital Warfare (EW) capabilities.
The brand new APG-85 is deliberate to include a few of the newest applied sciences obtainable, with unconfirmed rumors mentioning the potential of the adoption of Gallium Nitride (GaN) for the Transmit/Obtain (T/R) modules. The radar is supposed to defeat “present and projected adversarial air and floor threats” over the subsequent many years.
Northrop Grumman, which already manufactures the present APG-81 radar, additionally emerged because the developer of the APG-85. The JPO didn’t disclosed if this radar will probably be obtainable to all F-35 customers or if it’s going to stay a U.S.-only system.
Implications
The radar-less F-35s could be considerably constrained throughout operations. Whereas the F-35’s sensor fusion permits it to obtain concentrating on information from different networked platforms, the absence of an onboard radar would restrict unbiased air-to-air and air-to-ground mission functionality.
Such plane would doubtless be restricted to coaching, ferry, or restricted check roles till retrofitted with a purposeful sensor. This method would mirror earlier durations within the F-35 program when plane have been delivered with incomplete mission programs pending later upgrades.
At current, with out official particulars concerning the radar concern, many questions stay unanswered, together with the variety of plane delivered with out the radar and the timelines for each the supply of the brand new radar and the retrofit on these plane. Whether or not the present scenario signify a short-term integration hiccup or a extra intensive drawback will doubtless turn into clearer as official information emerges from the Pentagon and trade.
However, the introduction of the APG-85 stays a central aspect of the F-35’s long-term relevance towards evolving air protection and fighter threats. The brand new challenges nonetheless underscore the persevering with complexity of fielding superior capabilities inside a program of the F-35’s scale.
On the similar time, the problems additionally underscore how essential is the provision chain and the way points with one of many hyperlinks can have an effect on the rest of the chain. That is additional mirrored by the operational facet, as such points introduce non permanent functionality gaps that require retrofit applications and phased upgrades to be assessed.
