(Reuters) – Pentagon chief arms buyer Frank Kendall said the United States was close to a design fix for the Pratt & Whitney engine that powers Lockheed Martin Corp’s F-35 fighter jet after a major engine failure in June, and the cost would be “relatively minor.”

Kendall told reporters after a defense conference that the Pentagon was setting up test fixtures to ensure that the corrective action proposed by engine maker Pratt, a unit of United Technologies Corp was acceptable and adequate.

“I am getting, over time, more confident that we’ve got our arms around that problem and are solving it,” Kendall said.

Asked about the cost of addressing the issue that destroyed the engine on an Air Force F-35A model at Eglin Air Force Base on June 23, he said, “I don’t think it’s going to be a huge cost. I think it’s a relatively minor cost.”

Sources familiar with the program told Reuters on Tuesday that Pratt would begin testing the design change this week. The engine failure has been blamed on excessive rubbing by part of the engine during certain maneuvers.

The failure of Pratt & Whitney’s F135 engine grounded the entire F-35 fleet for several weeks this summer and prevented the newest and most advanced U.S. warplane from making its international debut at two UK air shows. Flights have resumed but with certain restrictions on speed and other maneuvers.

Pratt’s deliveries of the F135 engine have been on hold since the June 23 incident.

Kendall declined comment about separate contract negotiations under way with both Lockheed and Pratt about the next batches of planes and engines.

Pratt spokesman Matthew Bates had said on Tuesday that the company hoped to wrap up talks “shortly” with the Pentagon about the next two batches of engines.

SOURCE REUTERS