U.S. F-35s Won’t Hit 80 Percent Mission Capable Goal Amid Spare Parts Supply Problems

The U.S. government’s official decision to kick Turkey out of the Joint Strike Fighter Program may exacerbate these issues.

byJoseph Trevithick|
F-35 photo


Mark Esper, the nominee to become the next U.S. Secretary of Defense, has told Congress that F-35 Joint Strike Fighter fleets across the U.S. Air Force, Marine Corps, and Navy fleets will not reach an 80 percent mission capable rate goal by the end of the present fiscal year. Esper said that the main reasons for this were difficulties in sourcing spare parts and distributing them to units in a timely manner. 

His revelations come as the Pentagon moves ahead with efforts to find alternate suppliers for certain components for the stealthy fighters to fill the gaps left by the Turkish government, and the country's defense contractors by extension, getting kicked out of the F-35 program over its purchase of Russian-made S-400 air defense systems. This is a process that will cost the U.S. military between $500 and $600 million and the Pentagon is already raiding budgets specifically set aside for spare parts to help pay for it.

“Transparency (canopy) supply shortages continue to be the main obstacle to achieving this [readiness target]," Esper said in a written response to a question from the Senate Armed Services Committee, according to Breaking Defense. "We are seeking additional sources to fix unserviceable canopies."

A good view of the canopy on a US Air Force F-35A in the open position., USAF

The Senate Armed Services Committee held a nomination hearing for Esper on July 16, 2019. The United States has been without a formal Secretary of Defense since James Mattis resigned in December 2018. Then-Deputy Defense Secretary Patrick Shanahan subsequently became Acting Secretary of Defense and looked set to become Secretary of Defense until controversial details regarding his personal life emerged publicly in June 2019, after which he withdrew from the confirmation process.

In September 2018, Mattis had issued a memorandum demanding that the Air Force, Marines, and Navy do their utmost to get the mission-capable rates of their Joint Strike Fighter fleets up to at least 80 percent by the end of the next fiscal year. He also asked the Air Force to work on getting its F-16 Viper fighter jets and F-22 Raptor stealth fighters to this same readiness level. The Navy received the same instructions with regards to its F/A-18E/F Super Hornets and that service, along with the Marine Corps, got the same marching orders for its F/A-18 Hornets, too.

Fiscal Year 2019 ends on Sept. 30, 2019. The Air Force has already acknowledged that the F-22 will also not meet Mattis' readiness goal by that time, though its F-16s will, according to Breaking Defense. In April 2019, the Navy said it was getting close to the target with its Super Hornets. The status of the legacy Hornet fleets, which have also suffered from very low availability in recent years, is unclear. In 2018, the Navy decided to transfer 136 F/A-18s, which the service was already planning to divest, to the Marine Corps to help that service improve the readiness rates of its Hornet units.

Esper's admission that the F-35s will not reach the 80 percent mission capable rate by the end of September is not necessarily surprising, nor is the assertion that spare parts issues are the key factors. Official data made public earlier this year showed that Air Force, Marine, and Navy Joint Strike Fighter fleets continued to struggle with dismally low availability rates as recently as the end of last year.

A set of graphs showing average availability rates for all three F-35 variants across the Air Force, Marines, and Navy between May and November 2018., GAO

Between May and November 2018, just the lack of spares and problems with getting available parts to units in need left F-35s across the U.S. military unable to fly at all 30 percent of the time on average, according to a report the Government Accountability Office (GAO) released in April 2019. That same report also specifically noted the canopy problem that Esper highlighted in his response to the Senate Armed Services Committee.

A chart showing the average time for depot-level repair of an F-35 part as of November 2018 versus the objective turnaround timeframe of 60 to 90 days., GAO

"DOD found that the special coating on the F-35 canopy that enables the aircraft to maintain its stealth failed more frequently than expected, and that the manufacturer could not produce enough canopies to meet demands," GAO's review of F-35 "supply chain challenges" explained. "To address these challenges, the program is looking for additional manufacturing sources for the canopy and is considering design changes."

More damningly, GAO's analysts concluded that, given the state of the Joint Strike Fighter supply chain at the time, that U.S. military's F-35 fleets would never be able to get above a 70 percent mission-capable rate even under the best of circumstances, as outlined in the chart below. Lockheed Martin has since told Breaking Defense that it is working to mitigate the canopy supply chain and design issues.


“Newer F-35 aircraft are averaging greater than 60 percent mission capable rates, with some operational squadrons consistently at or above 70 percent," Lockheed Martin continued in its statement to Breaking Defense. "We’re taking aggressive action across the full F-35 enterprise to achieve the 80 percent mission capable rate target as soon as possible."

But the Pentagon's main F-35 Joint Program Office (JPO) may already be looking at new hurdles in meeting these readiness targets as a result of Turkey getting ejected from the program, which became the formal U.S. government position on July 17, 2019. The United States and other F-35 operators have concerns that Turkish forces flying the stealthy fighters and also operating the Russian S-400 air defense system could expose sensitive details about the jets' signatures and other capabilities.

"Turkey’s decision to purchase Russian S-400 air defense systems renders its continued involvement with the F-35 impossible," the White House said in a statement. "The F-35 cannot coexist with a Russian intelligence collection platform that will be used to learn about its advanced capabilities."

Unfortunately, Turkish defense contractors have been responsible for producing more than 900 components used in the construction of new F-35s. Suppliers in Turkey are the sole providers of around 400 of those items, including the jet's wide-area cockpit display. In June 2019, the Pentagon revealed that it was already working on a “disciplined and graceful wind down” of Turkish contracts related to the Joint Strike Fighter by the end of next year. In a press briefing on July 17, 2019, Ellen Lord, the Undersecretary of Defense for Acquisitions and Sustainment, said that, as a result, companies in Turkey were set to lose approximately $9 billion in deals across the lifespan of the F-35.

The first F-35A Joint Strike Fighter for Turkey on display at a rollout ceremony in June 2018., Anadolu Agency

While the United States has already been working on finding alternate sources for these parts, it won't be cheap. Lord said in her briefing that it will take between $500 and 600 million to complete the process. The Pentagon is treating the need to find new vendors for certain parts as an added "nonrecurring engineering cost" on top of what it is already budgeting to spend on buying additional Joint Strike Fighters, she added.

It's not clear if this includes $206 million in funds that the Pentagon has asked Congress for permission to shift into Navy budget accounts for the procurement of short takeoff and vertical landing F-35B and carrier-based F-35C variants, specifically to cover the costs of finding new suppliers. That same request, dated May 2019, but which only emerged earlier this month, also indicated that the Pentagon was planning to ask for another $155 million for the same reasons.

What was more notable about this request was that the money would come out of other parts of the budget set aside for the purchase of F-35 spare parts. The Pentagon argued that it had cut costs and ended up with a surplus of funds in this account. 

Between what was already known about the F-35's supply chain difficulties, together with Esper's latest comments about spare parts being central to the Joint Strike Fighter's continued readiness woes, it is hard to feel that Pentagon would have been well served by still using those excess funds for their intended purpose. At the same time, it's certainly true that mitigating the loss of Turkey and Turkish defense contractors from the F-35 program is also a very pressing concern. 

It remains to be seen just how much of an impact on the readiness of Air Force, Marine, and Navy F-35s this decision will have in the future. 

Contact the author: joe@thedrive.com