Marine Corps cutting F-35B buy for more F-35Cs: New aviation plan

An F-35B lands aboard Japan’s Izumo-class multi-functional destroyer JS Kaga (DDH-184) for the first time on Oct. 20, 2024. (Photo by Cmdr. Darin Russell.)

WASHINGTON — The Marine Corps is shifting the balance of F-35 Joint Strike Fighters it intends to buy, opting to purchase dozens more carrier-based variants in lieu of the short-take-off and vertical landing variant, according to the service’s new 2025 aviation plan. 

Moving forward, the Marines plan to buy a total of 280 F-35Bs rather than their previous objective of 353 aircraft. In turn, the service will purchase 140 F-35Cs rather than the previous objective of 67 F-35Cs. The total procurement objective of 420 F-35s remains the same.

“Per the TACAIR Transition plan, Marine Fighter Attack Squadron 232 (VMFA) and VMFA-323, VMFA-112, and VMFA-134 will now transition as F-35C squadrons. The program of record now includes 280 F-35Bs and 140 F-35Cs to support 12 F-35B squadrons and 8 F-35C squadrons,” according to the document, published Monday and signed out by Lt. Gen. Bradford Gering, the deputy commandant for aviation.

The new aviation plan states 183 F-35Bs and 52 F-35Cs have been delivered to the service thus far. The aviation plan acts as a high-level roadmap detailing the Marine Corps’ plans for its various platforms. Central to this new plan is the inclusion of “Project Eagle,” a multi-phase initiative spanning through 2040 that focuses on projects such as new warfighting concepts as well as the implementation of artificial intelligence.

“What Project Eagle does for us, as we look across three [future years defense programs] is it shows us where the trade space is,” Gering said last year.

The US Air Force has for years set its sights on buying 1,763 F-35As, a number that former Secretary Frank Kendall suggested before leaving office should be revisited down the road. The US Navy intends to buy 273 F-35Cs.

After publication of this report, F-35 manufacturer Lockheed Martin said in a statement that “We support the U.S. Marine Corps’ decision to adjust to an F-35 fleet configuration that best allows them to fulfill their critical missions with the world’s most advanced aircraft.”

F-35 Woes Continue, Pentagon Weapons Tester Finds

Meanwhile, the F-35 program is still plagued by a series of issues, from lagging readiness to sluggish software development, the Pentagon’s top weapons tester found in a recent report.

A leading issue for the tri-variant stealth fighter is its disappointing availability — measured by mission capable rates, meaning a jet could perform one of its assigned missions, or fully mission capable rates, meaning it can execute all of them — a critical issue for officials and a focus of a “War on Readiness” launched by the program in 2023. 

Despite concerted effort spanning several years, results have been mixed, according to a chart included in the report. The conventional takeoff and landing F-35A has seen declines in its mission capable and fully mission capable rates in recent years, which are well below targets. The short takeoff and vertical landing F-35B saw its mission capable rate decline and its fully mission capable rate plateau, where both metrics are still below objectives. Only the carrier-launched F-35C has seen measurable improvement, as its mission capable rate remained largely flat and its fully mission capable rate inched up, but both key measurements are also beneath program goals.

Another central problem for the program is software development, a key reason why officials previously took the unprecedented step of halting deliveries for a full year amid difficulties with a new upgrade known as Technology Refresh 3 (TR-3). According to the report, in some cases the program “has shown no improvement in meeting schedule and performance timelines for developing and testing software designed to address deficiencies and add new capabilities.”

Jets currently flying with the TR-3 upgrade are restricted to training, and officials are striving to ensure full combat capability can be delivered this year. Still, the program likely will not begin “dedicated operational testing” of the full TR-3 enhancement until “mid to late FY26, approximately two years after the configuration began delivery to the field,” the report says.

And even after years of production, military customers are still discovering quality escapes with aircraft, which the report notes should have been identified during the acceptance process. 

But there have been improvements in the manufacturing process as well: According to the report, the program has achieved a 47 percent reduction in scrap, rework, and repair time as well as a 63 percent reduction in quality escapes discovered from the aircraft’s production line between 2016 and 2023. 

The program has also generally improved upon some reliability metrics in recent years, indicating advances like more sturdy parts that don’t need to be removed as frequently.  

A spokesperson for Lockheed said in a statement that “Delivering the highest quality to the warfighter is foundational to our Lockheed Martin culture, and we remain focused on achieving 100% quality each and every day.” Regarding mission capable rates, the spokesperson said the aircraft “has demonstrated high combat and deployed readiness since data was collected for this report, in some cases more than five years ago.”

They added that information in the DOT&E report is “dated,” and that quality escapes could entail “minor items such as an incorrect serial number on paperwork.” The spokesperson also pointed to a previously announced internal investment of over $350 million to boost the program.

“These investments will enhance fidelity and capacity across our development, integration, and test labs, ultimately enabling us to shift defect discovery to the left,” they said.

In a statement, the head of the F-35 program, Air Force Lt. Gen. Mike Schmidt, said the report “highlights shortcomings without adequately addressing the corrective actions the JPO has taken to address the challenges. Every observation requires — and has received — a response from the JPO, and we have made tangible progress in remediating the issues in the report.”

Readiness is weighed down by what the program calls “degraders,” which can be factors like supply chain issues. Over the past year, according to Schmidt, the program has eliminated 20 of these degraders, though a “small number” of remaining degraders “mask tremendous progress that’s been made.” Additionally, Schmidt noted that deployed and operational aircraft achieve higher mission capable rates than the fleet when measured as a whole, though he acknowledged that “overall readiness rates remain unacceptable.”

Regarding TR-3, Schmidt said, “We are aggressively implementing comprehensive test plans to ensure this critical upgrade delivers cutting-edge capabilities to the warfighter.”

“While there is always room for improvement, the steps we have taken reinforce our dedication to providing the capabilities our warfighters need,” Schmidt said. “The F-35 program remains the cornerstone of our nation’s air superiority, and this report underscores both our accomplishments and areas for continued growth.”

An MV-22 Osprey for the Marines Corps undergoes an upgrade along Boeing’s production line in Philadelphia. (Michael Marrow/Breaking Defense)

V-22 Improvements

Elsewhere in the aviation plan, the Marines detailed several planned upgrades and modifications to its MV-22 fleet in the years ahead to better position the fleet to foresee material failures before they disrupt operations.

Those changes include the VeCToR upgrade, which deals with a number of obsolescence issues inside the cockpit; a new modernization plan, dubbed ReVAMP, to “ensure platform relevance” until the end of the aircraft’s service life; and redesigning the flight control computer.

With respect to the proprotor gearbox, which has been the focus of numerous mishaps in recent years involving the Osprey, the aviation plan states the Marines will “install sensors in critical areas of the PRGB and drive train to provide vibration signature data that will allow maintenance to forecast the failure of parts and plan to remove those parts prior to failure.”

“A more refined Triple-Melt steel will be the source material for the internal components of the PRGB which will drastically reduce the likelihood of material defects in critical gears and bearings,” according to the document. “A redesigned Input Quill Assembly (IQA) will reduce the incidence of the wearout mode observed in previous IQA failures that led to aircraft Hard Clutch Engagement (HCE) occurrences.”

UPDATED 2/4/25 at 12:06 pm with a statement from Lockheed Martin addressing the Marines’ new aviation plan.