The Joint Strike Fighter program now estimates a 4-5 month delay in delivering the aircraft’s fully functional software package and is working to recover that slippage after prioritizing work to support the U.S. Marine Corps initial operational capability (IOC) date of July 1.

The Marine Corps, the first Lockheed Martin F-35 customer slated to declare IOC, is using the 2B software package to stand up its first squadron of aircraft at MCAS Yuma, Arizona. Although the 2B is limited to employing three weapons—the 1,000-lb. GBU-32 Joint Direct Attack Munition, GBU-12 500-lb. Laser-Guided Bomb and Advanced Medium-Range Air-to-Air Missile AIM-120 series—the F-35B will surpass the current capability of the AV-8B Harrier jump jet and F/A-18C twin-engine Hornets, the Marines say.

All of the software testing needed to enable close air support (CAS) operations for the Marines—a primary mission, as the F-35B will support the Marine Air-Ground Task Force—is complete, says Lorraine Martin, F-35 executive vice president for Lockheed Martin. The entire 2B software package was expected to wrap up testing in January, but she says “single-digit” numbers of tests requiring specific conditions have yet to be finished. Completion of those was slated for February. 

Meanwhile, development of the 3i software package—2B functionality married with new hardware—has tied up much of the margin for the program. The U.S. Air Force plans to declare IOC between August and December 2016.

USAF Lt. Gen. Christopher Bogdan, the Pentagon’s program executive officer, says the initial remedy is effective for a fault that caused a catastrophic fire in an F-35A’s Pratt & Whitney F135 engine last year, but the program is seeking to improve it. The fix—producing the polyimide engine lining with a “trench” for stators in the third-stage integrally bladed rotor roughly 1/8th of an inch deeper—has been approved for production aircraft, according to Chris Flynn, who served as Pratt’s F135 and F119 vice president during the engine fault investigation. The company aims to deliver the first set of “pre-trenched” stators in February, he says. By the first quarter of 2016, Pratt hopes to have added the fix to all engines in the fleet already fielded. “Hopefully, we don’t have to talk about this that much any more,” he says, acknowledging the engine fire and subsequent fleet grounding cost the program time.

That problem delayed progress of the overall program about 1-1.5 months, Bogdan says.

Meanwhile, not all of the program’s early-production Lockheed Martin F-35s are likely to be modified to the final 3F software standard—which adds a variety of weapons and sensor fusion—by the targeted end of development in 2018. But once again, the slippage looks like it will be only months, Bogdan told reporters Feb. 24 at the Australian International Airshow at Avalon, near Melbourne. He stresses that the delays are, at worst, measured in months and do not suggest a change in the basic structure of the program or a need for more funds.

As for F-35 data stolen from industry via the Internet in 2010—reportedly by China— Bogdan asserts: “As far as I know, they were of a non-classified nature. It was basic information about the airplane that was unclassified.” But data security is still a concern, and there are constant efforts by outsiders to learn about the F-35, he adds.

Adversaries of the U.S., he says—without naming any—are good at copying the shapes of U.S. aircraft in building prototypes. But he notes that “one of the things that makes the F-35 special is what is inside the airplane, not outside the airplane. And I know that stuff is pretty safe.”

Difficulty in fusing the sensor data of several F-35s flying in formation is a major factor in the delay of the fully functional 3F software, says Bogdan. Another is the limited time available for testing the 3F version while the protracted development of the interim package, 3i, occupies the fleet of flight-test aircraft.

“My estimate is it is 4-5 months late,” Bogdan says, referring to 3F. That does not yet mean that the timetable for other elements in the program needs to be shifted, he says, without naming them. “We are working as best we can to drive that [slippage] back.”

Last among the U.S. F-35 operators, the Navy plans to declare IOC in August 2018 with 3F, marking the end of the main development phase of the Joint Strike Fighter program. The required delivery date for 3F is presumably about two months before the Navy’s IOC date. The delay, if not mitigated, would push the Navy’s IOC out to the end of 2018 or the beginning of 2019.

The 3i package is five months late, but that is not yet imperiling the Air Force’s plans, because more than six months of reserve was built into the schedule, says Bogdan. “It is right on the edge right now,” he notes. 

He also says he is “pretty confident” that the Marines will declare IOC in the summer, a target that allows a few weeks’ delay. That is in keeping with a theme in his account of the program: Whereas it was years late before its timetable was reset in 2010-11, the many instances of lateness that he now sees are measured in days, weeks and sometimes months.

This fairly close adherence to the schedule has not been achieved by skimping on testing, Bogdan says, though conservatively scheduled tests were dropped when they proved unnecessary. Nor have capabilities been removed from the F-35 to get it over the line on time. 

Despite his confidence that the IOC for the Marines will be achieved this year, Bogdan says at least four of roughly 10 issues needed to reach that goal are late. These include the Automatic Logistics Information System (ALIS); “modeling the airplane so that they have the right combat configuration,” as Bogdan puts it; simulator delivery and some of the software. Preparation of the mission planning system and mission data files is also running late. ALIS 2.0, the version that will allow for centralized and distributed fleet oversight, is slated for delivery in March, Martin says. Likewise, the compact hardware for ALIS designed for use on small amphibious ships is expected to be ready for the Marines IOC date in July, she adds.

Meanwhile, flight testing has advanced from flying aircraft alone to flying them in groups of two and four. This involves sensor fusion, which Bogdan describes as ensuring that all pilots see the same tactical picture that any one of them sees.

“What we have found is linking four airplanes together in the same battle space—we know how to do that,” he says. “We are having problems having all four of those guys see the same picture.”

The companies building and supplying parts for the F-35 are also facing great challenges in ramping up the production rate from 36 last year to more than 120 in 2020. The depots will be new, too. Those factors contribute to the challenge of modifying the early aircraft—which must be changed as a matter of course, because of what is learned in the testing effort in which they are used.

“In 2018, I will probably be 30 airplanes shy of where I want to be,” says Bogdan. But the delay is on the order of one month. 

Availability of the ever-growing test fleet increased to 65-70% in late 2014 and early 2015 from 35-40% about 18 months ago, when an effort to improve this aspect of program performance began.