Possible Fuel Leak Curtails F-35 Flight

The pilot flying the F-35A fighter built by Lockheed Martin Corp cut short the planned 90-minute flight when he noticed a visible substance coming off the left wing of the aircraft, an Air Force spokesman said.

The aircraft returned safely to the base after just 15 minutes, and mechanics are still inspecting the radar-evading single-engine plane to determine if a fuel leak occurred, he said.

The Air Force cleared initial flights of the F-35 at the Florida air base, where Air Force and Marine Corps personnel will be trained to fly and maintain the new warplane, which is still in development.

The curtailed flight was another setback for the $382 billion F-35 program, which the U.S. Defense Department is restructuring for a third time to allow more time for development and testing.

Officials familiar with the program said the issue was typical of technical glitches that occur when new military planes are being developed. The program did receive a strong showing of support last week from eight international partners who are funding the plane's development during a meeting in Washington.

Air Force Colonel Andrew Toth, commander of the 33rd Fighter Wing, said the first flight was still a milestone for the training program.

"Unfortunately things happen," he said in a statement. "Our pilot did the exact right thing in returning the jet back to Eglin. Although there were issues, we are doing whatever we can to move the program forward safely and effectively."

Lockheed referred all questions about the issue to the Air Force.

Initial training flights were due to begin at the Florida air base last November, but those plans were put on hold after the Pentagon's chief weapons tester raised what he called "serious concerns" about plans to start pilot training.

The Air Force has since adopted a more phased approach to training to address the Pentagon's concerns.

Test pilots who have been flying the plane during development flight testing at Edwards Air Force Base in California and a Navy air base in Maryland will fly the planes initially as they test out the training syllabus for the program and carry out local area orientation.

"We will continue to make steady progress towards our goal of standing up a world class training program at Eglin," says General Edward Rice, commander of the Air Force's Air Education and Training Command.

Lieutenant Colonel Eric Smith, an F-35 test pilot who was at the controls, says the team had trained many times in an F-35 simulator to prepare for all sorts of emergencies that could occur in flight.