Lockheed is building three variants of the F-35 for the United States and eight countries that funded its development: Britain, Canada, Australia, Norway, Denmark, Italy, Turkey and the Netherlands. Israel and Japan are also buying the planes.

Besides the Marine Corps, Britain and Italy also plan to buy the F-35B.

All the aircraft will have to undergo an initial checkout flight before they can resume testing or training flights, said a defense official who was not authorized to speak publicly.

The official said it was unclear how the grounding would impact the overall test program for the F-35B since that model had been a bit ahead of schedule with flights before the grounding. “There will be some impact for sure. Thirty days of testing is 30 days,” said the official.

The Pentagon continues to analyze equipment made by Stratoflex and remains in discussions with Pratt about the cost of the detailed inspections and repairs, the official said.

Matthew Bates, a spokesman for Pratt, welcomed the decision to resume flights of the F-35B and said the root cause had been corrected. “We took additional steps with our supplier to ensure hose integrity for the entire fleet, and we are confident in the integrity of the overall propulsion system,” he said.

Bates had no immediate comment on who would pay for the cost of the inspections and repairs resulting from the incident.

So far, 82 hoses from the F-35B aircraft have been shipped to an independent company in Minnesota for CT scans. Initial analysis showed 10 of 36 hoses were overcrimped and needed repairs, said the official, adding that five sets of hoses had been cleared for use.

Pentagon and Navy officials have adjusted the requirements for the hoses after studying the performance of a test engine, being used by Pratt & Whitney, that was found to have an overcrimped hose but logged 1,600 hours of use without a problem.