The F-35 flight test program has missed about 30 "flight test opportunities," or scheduled flight test sortie slots, since the fleet remains on the ground after an F-35A caught fire June 23 while preparing for takeoff, says U.S. Air Force Lt. Gen. Christopher Bogdan, the program executive officer overseeing the project.

Two days after the fire, local commanders of F-35 bases across the country had all decided to halt flights of the single-engine fighter. This included a stop on all flights of each of the three variants, including at manufacturer Lockheed Martin. Additionally, Pratt & Whitney has stopped tests of its F135 engine, thought to be the source of the fire.

The incident marks what will likely be the first F-35 Class A mishap, a term associated with damage over $2 million. The pilot safely egressed.

"Is it a big deal in the big scheme of things? It is not," Bogdan said of the effect of the stand-down thus far. To catch up, testers can simply add a couple of flights weekly for a short period — but only if flights resume soon and if no major shortcomings are found in further flight tests.

The F-35C, designed for use on U.S. aircraft carriers, is the variant most sensitive to schedule disruptions at the moment because it is being tightly managed leading up to its initial at-sea trials on an aircraft carrier this fall. "That is the thing to make up the most time on" once aircraft return to flight, Bogdan says, noting carrier schedules are rigid. "Their schedule is not going to flex for us."

If the F-35C misses its window for sea operations in the fall, Bogdan says there are backup opportunities for those tests in 2015.

No software development has been delayed due to the fire and Bogdan predicts commitments to declare initial operational capability for the Marine Corps next summer, followed by the Air Force in 2016, will be met.

While the aircraft remains on the ground, Bogdan has directed that planned inspections and quick modifications needed for the jets — some are the oldest in the fleet, from the first production lots — be done to allow for more flight time later in the schedule.

Meanwhile, the United Kingdom has not yet approved its F-35B – BK-3 – for flight from Eglin AFB, Florida, to NAS Patuxent River, Maryland. BK-3 and three U.S. Marine Corps F-35Bs were to meet up this week and together make the historic transit across the Atlantic Ocean to the United Kingdom for the program’s international debut at the Royal International Air Tattoo and Farnborough air show there. Though the Marine Corps flew its Bs to Patuxent River June 27, the U.K. has not yet approved its aircraft to fly.

Program officials must arrive with the jets next week in time to conduct validation flights ahead of flying demonstrations at both events.