F-35 jets flying with the TR-3 upgrade at Edwards Air Force Base, California.

F-35 jets flying with the TR-3 upgrade at Edwards Air Force Base, California. Courtesy Lockheed Martin-Edwards team

F-35 test squadron works to wring out upgrade problems

Delays to the TR-3 upgrade have dozens of jets on hold.

EDWARDS AIR FORCE BASE, California—With deliveries of new F-35s on hold while bugs are worked out of a planned upgrade, the plane’s lead test squadron is doing its part to spot problems where the new hardware and software interact. 

As the lead developmental flight test unit for the F-35 program, the 461st Flight Test Squadron sits at the “nexus” between development and the operator, said squadron commander Lt. Col. Philip “Joker” Jackson. 

“Even if we're going to get something that doesn't entirely work, because we're test, because we can fly it, we're going to take it up, and we're going to discover what we can and try to rip off all those Band-Aids early,” Jackson said in an interview here. 

Jackson’s squadron is testing a suite of hardware and software improvements, known as Technology Refresh 3, or TR-3, that will be the backbone for Block 4—the Pentagon’s effort to equip the F-35 for fights in the decades to come. New F-35s are being produced with TR-3 gear—but the Pentagon has stopped accepting them until the hardware can reliably run the current TR-2 software, a spokesman for the F-35 joint program office said.

TR-3 will bring 20 to 25 times more computing power, plus more memory and a new panoramic cockpit display, said Maj. Adam "Hawk" Fuhrmann, the squadron’s chief of projects.

If you look at the F-35 as a flying supercomputer, “you're really replacing all the major components of the computer,” Fuhrmann said. 

Jackson’s squadron, which currently has 12 F-35s of all three variants, swaps aircraft every six months or so with the Pentagon’s other test sites, mainly the test squadron at Naval Air Station Patuxent River, Jackson said.

In January, the squadron took the F-35 for its first flight in the new configuration, an “important milestone” that uncovered software problems “the contractor did not identify in software labs,” according to a recent Government Accountability Office report. That has tightened the program’s timeline to complete additional tests and fix software problems.

Since the first flight, the squadron has flown the new configuration 59 times, Jackson said. 

But out of 59 tests, only seven flights have fully counted toward the 214 needed to complete developmental testing. 

“We have specific objectives that we're trying to knock out and so we have not been able to knock out a lot of those yet,” he said. “We do 40 missions a month, and we are able to do as many of those TR-3 as possible that would support the testing. And right now, the aircraft and the software is not stable enough for us to anywhere come close to that throughput.” 

Jackson’s squadron averages about 40 test flights a month. Once TR-3 hits its stride, the unit will devote about 30 of those flights to reaching the end goal of 214.

The squadron has not been maxed out for testing capacity, but if it was, there are “all kinds of levers we could pull for surging,” Jackson said, so testing at Edwards wouldn’t be a bottleneck to TR-3 production.

“I say we're developmental test, not development, and so we do sit right there at the edge of it. We try our best to speed things along, but at the end of the day, we can only test things that are stable,” Jackson said. 

The squadron is ready to go faster, Fuhrmann said, and is prepared for when the TR-3 technology is stable enough to reach 30 missions a month.

Right now, the problems the squadron is working through are not specifically on the hardware or software side, but the “interaction of both,” he said.

“What we're going through right now is trying to drill down on where some of those interactions are causing that instability just to get us to a stable platform,” he said. ”There's a lot—an order of magnitude—more technology in these aircraft than previous generations, and with that comes a lot more complexity that you have to work through.”

However, TR-3 doesn’t have to reach 214 flights before it’s deemed ready for operations. Similarly, the F-35’s current computing system, TR-2, is flying even though testers haven’t finished all of its required developmental tests. 

“TR-2 is a very important thing and if you hear a lot of the generals, that's the one we're going to fight with currently,” Jackson said. “It's going to be a long time till TR-3 is carrying that load.”

Edwards will keep sustaining the development of TR-2 as long as those aircraft are in the fleet, until “whatever number of those jets are converted to TR-3 kits, whenever that happens,” Fuhrmann said. 

TR-3 software and hardware improvements are already one year behind schedule, and the Pentagon has recently said it will not accept new F-35s from Lockheed Martin until TR-3 testing is complete—meaning more than 80 F-35s could be left in limbo. Deliveries of new F-35s are on hold until December at the earliest and April at the latest, the JPO said. Lockheed will have to sit on 45 jets if the delay extends to December and 81 jets if it extends to April, as the company’s contract stipulates it must deliver nine planes per month with the tech upgrade.

To get deliveries flowing again, the program first has to get the new hardware running with the old software, TR-2.

“Although we cannot provide the metrics involved due to security concerns, at a minimum TR-3 must meet TR-2 equivalency before it can be accepted for operational use,” JPO spokesperson Russ Goemaere said in a statement. 

The squadron is flying jets that have been retrofitted to TR-3, not new TR-3 jets, so the hold shouldn’t affect Edwards, Jackson said. 

Edwards will eventually get new jets off the line for “future development of TR-3,” but when those new builds will get released is up to the JPO and Congress, Fuhrmann said. 

Testing with new TR-3 jets will be “critical,” Fuhrmann said. “Getting new hardware here to flight test—that'll allow us to rapidly iterate with Lockheed and to field faster.” 

While Edwards continues testing the new tech for F-35s, back in D.C., lawmakers are deciding whether to fund a new, adaptive engine for the F-35 or press on with Pratt & Whitney’s proposed upgrade to the current engine—a discussion that became a public spat between defense companies in recent weeks.

From a pilot’s perspective, the current engine is “fantastic” for today’s needs, but there’s no denying it’s exceeding the plane’s cooling capabilities and must be improved for the future, Fuhrmann said.

When asked about the squadron’s perspective on what engine the aircraft needs, Fuhrmann said “I’d test whatever the JPO determines is the best route going forward for the jet.” 

No matter the engine, Jackson said, “we love testing stuff” and “we have some pretty good airspace for it too.”

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