Less than a week after the Pentagon’s entire fleet of F-35 Joint Strike Fighters was temporarily grounded to investigate a suspect fuel tube, the majority of the aircraft are back to flight-ready status, officials said Oct. 15.

More than 80 percent of domestic and internationally based F-35s have been cleared and returned to flight operations, said Joe DellaVedova, spokesman for the F-35 joint program office (JPO) in an emailed statement on Monday. All U.S. services and international partners have resumed flight operations with those cleared aircraft, he added. BF-17, Major Richard "BC" Rusnok & BF-18, LtCol Jon "Miles" Ohma

On Oct. 11, the JPO announced that the office has grounded every F-35 aircraft in both the U.S. and international fleets after a suspect fuel tube was detected during the investigation of a crashed F-35B vertical take-off and landing variant in September in South Carolina. (Defense Daily) The cause of that accident remains under investigation by the aircraft mishap board.

Pratt & Whitney, a subsidiary of United Technologies [UTX], builds the F135 engine for the Joint Strike Fighter. A spokesperson told Defense Daily last Thursday that the company was working closely with the F-35 joint program office and with prime contractor Lockheed Martin [LMT] to address the issue. DellaVedova called it “an isolated incident which is being quickly addressed and fixed.”

DellaVedova said Monday that the company is “rapidly procuring more parts to minimize the overall repair timeline for the remaining jets.” Current inventory can restore about half of the impacted jets to flight-ready status, and remaining aircraft should be cleared over the coming weeks, he added.

The program office does not anticipate an impact to future F-35 deliveries, and remains on track to meet a target of 91 deliveries in fiscal year 2019.