EGLIN AFB -- The Marine variant of the F-35 fighter jet resumed flying Thursday after an almost 30-day suspension.
The planes were grounded nationwide last month after an engine malfunction occurred during a takeoff at Eglin.
The suspension, the longest in the history of the F-35, was caused by an improperly crimped hose, or fueldraulic line.
"We're very excited to get back to the flying business," Marine Col. Arthur Tomassetti, vice commander of the 33rd Fighter Wing, said Thursday.
On Jan. 16, a pilot was starting his takeoff when one of the hoses that connect to the engine malfunctioned. The pilot was able to stop the jet safely.
Flights were suspended Jan. 18 to investigate the malfunction. On Wednesday, the Joint Strike Fighter Program Office at the Pentagon announced that all F-35Bs had been cleared to fly upon re-installation of compliant hoses.
About 80 hoses from the planes, supply shelves and the manufacturing process were pulled for inspection.
So far about 10 have failed, Tomassetti said.
The hoses that have passed are being returned to bases. Eglin has received one set of two hoses and reinstalled them in the F-35B that took off Thursday.
The F-35B, capable of short takeoff and vertical landing, is the Marines' variant of the military's newest fighter jet.
The problematic hose pumps fuel that is used to swivel a rear nozzle from pointing back to pointing down. That is part of the process that enables the short takeoffs and vertical landings.
The Air Force and Navy versions of the jet were not affected by the malfunction.
Across all variants, the planes have been grounded only four other times, the longest for 15 days.
Several Marine pilots had just finished their ground training and were ready for their first training flights in the jet when the planes were grounded last month, Tomassetti said.
They lost about three-and-a-half weeks while inspectors worked through the process, which has slowed their training timeline.
"With anything this new you have to be a bit overly cautious. We let the system do what it had to do; we were just in the waiting game," Tomassetti said. "Now our challenge is how are we going to make up for lost time."
He said there are only so many hours in a day and the weather is still a factor, but the 33rd will look for creative ways to accelerate the training and get the students caught up.
Tomassetti hopes they will be caught up by the time the next batch of students are ready to fly the jets in mid-May.
Another set of two hoses was expected to arrive at Eglin on Thursday night.
"We'll start to see one or two come in, hopefully per day, until we get all the airplanes back with the good hoses," he said.
Even if some of the hoses for Eglin's 13 F-35Bs don't pass inspection, the company that produces the part is ready to deliver a new batch by the end of the month, so all the planes should be back up by then, Tomassetti said.