The newest F-35 Joint Strike Fighters are now able to carry out more elaborate training missions, but the government is withholding millions of dollars in payment to Lockheed Martin until the jets can fight in combat.
Lockheed Martin has upgraded the software in its latest batch of F-35s to handle “more robust combat training capability,” the F-35 Joint Program Office and Lockheed said in a joint statement Thursday. Previously, these F-35s could only carry out “initial training capability” using a partial version of the upgrades known as Technology Refresh 3.
The government refused to accept delivery of the new TR-3 fighters from Lockheed starting in July 2023 due to software integration problems and some hardware shortfalls. Lockheed continued to build F-35s while hunting for a solution to the TR-3 problem and stored them at its Fort Worth, Texas, facility.
Lockheed developed a partial version of the TR-3 software it referred to as “truncated,” which would allow the jets to fly basic training missions — but not in combat. The government concluded the truncated software worked well enough to start accepting the jets and deliveries resumed in July 2024.
TR-3 upgrades include better displays, computer memory and processing power, which are necessary for a more expansive upgrade known as Block 4. In addition to allowing the F-35 to carry more weapons, the Block 4 upgrades will allow the jets to better identify targets and conduct electronic warfare.
Top Air Force officials and Lockheed Martin last month promised further improvements to the F-35 will come.
But the new jets will likely not be able to fly into combat until 2025, and that will cost Lockheed in the meantime.
The JPO said Thursday that until TR-3′s combat capability is qualified and delivered, the government is withholding about $5 million per jet in payments to Lockheed Martin. Those withholdings were negotiated as part of the government’s agreement with Lockheed to accept and deliver F-35s with combat training capability.
The newest F-35A fighters, which the U.S. Air Force flies, cost about $82.5 million. New F-35Bs — the short-takeoff and vertical landing variants flown by the U.S. Marine Corps — cost about $109 million, and the F-35Cs the U.S. Navy and Marine Corps use on aircraft carriers will cost about $102.1 million.
The JPO and Lockheed also said the company and its industry partners “are making significant investments in development labs and digital infrastructure that benefit the F-35 enterprise’s speed and agility in fielding capabilities to the most advanced and connected fighter jet.”
The yearlong delays in delivering an unspecified number of F-35s have caused ripple effects throughout the Air Force and the Joint Strike Fighter program.
Gen. James Hecker, commander of U.S. Air Forces in Europe, said in July the TR-3 delays had led to a “slowdown” in the number of F-35s arriving at RAF Lakenheath in England, the home of the service’s two European-based F-35 squadrons. He said fewer than a dozen jets had been delayed.
“Don’t think that the TR-3 problems are over,” Hecker said at the Royal International Air Tattoo air show at RAF Fairford in England. “We do have a working software in TR-3 that is definitely good enough for training. … But there’s more to go.”
Newly delivered TR-3 jets would likely be sent to training bases, according to Hecker. Combat-capable jets flying training missions at those bases would then probably be transferred to Lakenheath.
And since TR-3 is necessary to put Block 4 upgrades in the jets, the delays have slowed down the next series of F-35 modernizations.
Andrew Hunter, the Air Force’s acquisition chief, also told reporters at the RIAT air show that the service was not paying full price for the incomplete jets.
“We will not pay for that which we have not yet received,” Hunter said.
Stephen Losey is the air warfare reporter for Defense News. He previously covered leadership and personnel issues at Air Force Times, and the Pentagon, special operations and air warfare at Military.com. He has traveled to the Middle East to cover U.S. Air Force operations.
