The Marine Corps has received six F-35Bs without the AN/APG-85 radar. This decision highlights the delays in the Block 4 program and temporarily compromises their operational readiness.
The United States Marine Corps has accepted six new F-35Bs without their primary radar. The information was confirmed on June 23, 2026, before the U.S. Senate by Lieutenant General Gregory Masiello, head of the F-35 Joint Program Office. The aircraft are awaiting Northrop Grumman’s new AN/APG-85 radar, which is set to replace the AN/APG-81 as part of the Block 4 modernization. Without this sensor, they can fly but do not have their full range of detection, tracking, fire control, and electronic warfare capabilities. They therefore cannot be considered fully operational. This situation stems from a mismatch between aircraft production and the availability of their new radar. It also reveals a deeper challenge: the F-35’s modernization requires more electrical power, cooling, software, and testing than the initial architecture had anticipated.
Confirmed Before the U.S. Senate
The information no longer comes from an industry leak or a photograph taken near the Fort Worth plant. It was confirmed under oath before the Air and Land Subcommittee of the Senate Armed Services Committee.
On June 23, 2026, Senator Mark Kelly asked Lieutenant General Gregory Masiello whether the Marine Corps was accepting aircraft without radar. The F-35 program manager replied that six aircraft had indeed been delivered with no radar installed. He also confirmed that the service was awaiting the AN/APG-85.
Mark Kelly then asked whether these aircraft could be considered fully capable of performing all their missions. Gregory Masiello acknowledged that he would not classify them as “Fully Mission Capable.” The term remains an administrative one. The reality is more straightforward: an F-35 without radar is not fully combat-capable.
These aircraft can be deployed, maintained, and used for certain activities. They can be used for crew familiarization or for flights that do not require the full mission system. However, they do not have the configuration intended for a full combat mission.
This development does not, therefore, mean that the Marines intentionally ordered a fighter jet without radar. It means that the government accepted airframes that were completed before the delivery of essential equipment.
The Central Role of the AN/APG-85 Radar
The AN/APG-85 is developed by Northrop Grumman. It is intended to replace the AN/APG-81, which is installed on the majority of F-35s currently in service.
Northrop Grumman describes the AN/APG-85 as a next-generation multifunction sensor compatible with all three versions of the F-35: the conventional F-35A, the short takeoff and vertical landing (STOVL) F-35B, and the carrier-based F-35C.
The manufacturer states that the radar is designed to improve the aircraft’s tactical situational awareness, survivability, and effectiveness against current and future air and ground threats. It is one of the key components of the F-35 Block 4 modernization program.
However, publicly available data remains limited. The number of transceiver modules, radiated power, frequencies used, detection range against various targets, and jamming resistance performance have not been disclosed. Any specific figures circulating regarding these points should therefore be treated with caution.
How an AESA Radar Works
The AN/APG-85 is an AESA radar, short for Active Electronically Scanned Array. Its antenna consists of a large number of electronic modules capable of transmitting and receiving signals.
A mechanical radar physically points its antenna toward the area to be monitored. An AESA radar shifts its beam electronically. This process is nearly instantaneous. The system can quickly change its direction, frequency, and waveform.
This architecture offers several advantages. It allows for the simultaneous tracking of multiple targets. It reduces the time required to switch from an air-to-air mission to an air-to-ground mission. It improves measurement accuracy. It also increases fault tolerance, as the failure of a few modules does not necessarily render the entire antenna inoperable.
An AESA radar can also divide its operations among several functions. It can search for aircraft, produce a detailed image of the ground, track moving vehicles, or participate in electronic warfare operations.
This flexibility is essential for the F-35. The aircraft is not merely designed to fire a missile at a target detected ahead of it. It must collect data, compare it with data from its other sensors, share it, and build a coherent picture of the environment.
Expected Missions for the New Sensor
The current AN/APG-81 already performs several functions. It provides search and tracking of air targets. It assists with fire control. It produces radar images of the terrain. It can detect certain moving targets and participate in electronic warfare missions.
Northrop Grumman also describes the AN/APG-81 as an electronic platform capable of performing protection, electronic support, and electronic attack functions. The radar is therefore not only used to detect an aircraft or a ship; it can also analyze the electromagnetic environment and help disrupt an adversary’s systems.
The AN/APG-85 must, at a minimum, maintain these functions and adapt them to more recent threats. It must handle weaker signatures, more jammed environments, and an increasing volume of data. It must also support the integration of new weapons and new Block 4 capabilities.
The exact range remains classified. It would therefore be misleading to claim that the AN/APG-85 will detect a specific target at a specific distance. Radar range depends on many factors: the target’s size, signature, altitude, orientation, interference, weather, the selected mode, and the quality of the signal processing.
The Delay That Caught Up with the Assembly Line
The problem stems from a mismatch between two schedules. Lockheed Martin continues to assemble the aircraft. Northrop Grumman is responsible for supplying and certifying the new radar. When the airframes are ready before the sensor, the program must choose between several undesirable options.
It can slow down or halt the assembly line. It can store the aircraft at the manufacturer’s facility.
It can temporarily install older equipment, if the configuration allows it. Finally, it can accept the incomplete aircraft and plan to upgrade them later.
The F-35 Joint Program Office has opted for this last option for the six F-35Bs in question. This decision avoids further production delays. However, it shifts the problem to the units, maintenance centers, and future modification facilities.
This is yet another example of the tension between development and production. This approach involves manufacturing equipment even though its development or testing is not fully complete. It can accelerate entry into service once everything is functioning properly. It leads to costly rework when components arrive late or require modifications.
The exact cause of the delay remains partially undisclosed
The public record does not allow the delay to be attributed to a single failure or a single manufacturing defect. Northrop Grumman’s schedule is behind that of the airframes, but the program’s technical details remain largely classified.
We must therefore avoid overly simplistic explanations. The problem is not necessarily limited to a component shortage or a manufacturing difficulty. A modern radar must be manufactured, integrated, cooled, powered, tested, and certified alongside the aircraft’s mission software.
The sensor must also communicate with the Technology Refresh 3 computers. This new computing architecture provides more memory and processing power. It forms the electronic foundation necessary for Block 4 capabilities.
The Government Accountability Office had already noted that Technology Refresh 3 had accumulated a delay of about three years. The identified causes included hardware, software, and integration difficulties. The radar delay is therefore part of a modernization effort that is already on shaky ground.
Electrical and Thermal Constraints Are Becoming Critical
The Senate hearing revealed another important point. The F-35 is approaching the limits of its ability to generate electricity and dissipate the heat produced by its systems.
Mark Kelly mentioned a current capacity of nearly 30 kilowatts and a requirement of approximately 32 kW for the Block 4 configuration. Gregory Masiello explained that this configuration would use virtually all available capacity. This would leave almost no margin.
The senator also cited a future requirement of 62 kilowatts. The program manager indicated that the long-term requirement was between 62 and 80 kW.
These figures must be interpreted correctly. They do not necessarily correspond to the power consumption of the radar alone. They pertain to the overall evolution of the F-35’s electrical and thermal systems. They include the requirements of the radar, computers, electronic warfare systems, and future equipment.
Gregory Masiello clarified that the new comprehensive power management and cooling system would not be available when the first AN/APG-85 radars are installed. He also noted that the radar could be installed without waiting for this full modernization.
This means that the AN/APG-85 will be able to operate in an initial configuration. The issue will arise primarily when all Block 4 capabilities and subsequent upgrades need to be used simultaneously. A system without thermal reserve risks limiting the duration of certain transmissions, the available power, or the addition of new functions.
Capabilities Lost Without Radar
The F-35 is equipped with other sensors. It can receive information from other aircraft, ships, ground-based radars, or command systems. It also has electro-optical capabilities and passive sensors.
This equipment does not fully replace the primary radar.
The F-35B Can Fly but Cannot Fight Normally
Without radar, the aircraft loses much of its autonomous ability to search for, identify, and track targets. It cannot normally execute all planned fire control sequences.
A data link can transmit the position of a threat to the aircraft. However, it does not always guarantee the quality, update frequency, or accuracy required to use all weapons. Certain missions require a target track generated or confirmed by the aircraft’s own sensors.
In air-to-ground missions, the lack of radar also deprives the crew of certain modes of mapping, designating, and tracking moving targets. Electro-optical sensors remain useful, but their performance is more dependent on weather, visibility, and approach geometry.
The aircraft does not become blind. It becomes heavily dependent on external sources and loses some of its tactical autonomy. This dependence is particularly problematic in a contested environment, where communications may be jammed or interrupted.
Data fusion remains limited
The F-35 is often described as a flying sensor system. This description is justified by its ability to combine information from multiple sources.
However, data fusion does not create intelligence out of thin air. It organizes, compares, and prioritizes the available information. When a major sensor is missing, the system has less data to fuse.
The absence of radar therefore reduces the quality of the tactical picture. It limits long-range active detection. It also diminishes the possibilities for correlating an electromagnetic signal, an infrared image, and a radar track.
This degradation affects not only the pilot but also other units in the network. An F-35 can transmit the information it collects. Without radar, its contribution to the collective tactical picture becomes weaker.
The Industrial Decision to Accept Incomplete Aircraft
The acceptance of the six aircraft is driven by industrial logic. An aircraft in storage at Lockheed Martin takes up space, ties up personnel, and blocks certain payments. An aircraft transferred to the government can begin certain operations, even if it remains incomplete.
This decision also allows the manufacturer to maintain the production line’s pace. Halting assembly on such a massive program would trigger a domino effect among hundreds of suppliers.
The decision remains debatable, however. An administrative delivery does not equate to military capability. An aircraft counted in inventories may give the impression that the fleet is growing, even though it cannot perform all its intended missions.
Lieutenant General Masiello himself acknowledged that these aircraft should not be classified as “Fully Mission Capable.” This distinction is important at a time when the program is seeking to improve its availability statistics.
According to the Government Accountability Office, the average rate of aircraft capable of performing at least one mission fell from 67% in 2021 to 44% in 2025. The rate of aircraft capable of performing all their missions fell from 38% to 25% over the same period.
The six aircraft without radar do not account for this overall decline. Their number remains too small. However, they illustrate the same problem: the program is delivering or operating airframes that do not always have all the necessary equipment, software, or parts.
The Hidden Cost of Retrofit Installation
The radars will have to be installed after delivery. This operation will involve more than simply placing an antenna in the nose of the aircraft.
Technicians will need to integrate the sensor, connect its electrical circuits and cooling systems, load the appropriate software, and verify its compatibility with the mission computers. The radar will then need to be calibrated and tested.
Ground tests will be necessary. Test flights may also be required to verify the system’s performance under various conditions. Finally, the program will need to update the technical documentation and train the maintenance crews.
This industrial catch-up effort will consume man-hours and already limited maintenance capacity. It could also ground the aircraft just as the Marine Corps is ready to integrate them into its squadrons.
The exact cost of these operations has not been made public. It will depend on the installation location, the extent of modifications required, the availability of equipment, and the maturity of the software.
Accepting the aircraft now therefore does not eliminate the cost of the delay. It merely shifts it over time and spreads it across the manufacturer, the government, and the units.
The Worrying Signal Sent by Six Aircraft
Six aircraft represent a small fraction of a global fleet exceeding 1,300 F-35s. The program manager indicated that more than 800 aircraft were in the U.S. inventory as of June 2026.
However, the problem would be poorly assessed if it were reduced to just these six airframes. The decisive factor is the ability of Northrop Grumman and the F-35 Joint Program Office to prevent the delay from spilling over into subsequent batches.
If airframe production continues to outpace radar production, the number of incomplete aircraft will increase. The program will then have to choose between more partial deliveries, extended storage, or a slowdown in the production line.
The precedent set by Technology Refresh 3 illustrates the risks of such a situation. F-35s were stored for months because their new IT architecture was not yet ready for fully operational delivery.
A repeat of the same scenario with the radar would demonstrate that the problem is no longer limited to a single component. It would affect control over the entire Block 4 schedule.
The Harsh Lesson of the Block 4 Program
The F-35 remains a technologically advanced aircraft. Its radar, passive systems, stealth capabilities, and communication capabilities give it a central role in U.S. and allied forces.
However, this sophistication demands very strict industrial discipline. A modern aircraft cannot be considered complete simply because its airframe, engine, and landing gear have been assembled. Its military value depends on its software, sensors, cooling systems, and their integration.
The delivery of six F-35Bs without radar shows that production has once again outpaced the full maturity of a critical piece of equipment. This allows the production pace to be maintained, but it does not immediately result in six additional combat-ready fighters.
The most concerning issue is not the temporary absence of six antennas. It is the accumulation of interdependencies between the AN/APG-85 radar, Technology Refresh 3, Block 4 software, the engine, and thermal management.
Any delay in one of these components can block or limit the others. The program will not be able to resolve this issue by increasing the number of administrative deliveries. It will have to demonstrate that the radars are arriving, that installations are proceeding quickly, and that the aircraft are actually regaining all the capabilities for which they were purchased.
War Wings Daily is an independant magazine.