THE BURNED OVER DISTRICT

The Pentagon thinks they may finally have figured out how to make the F-35 fly like a real jet plane.

A fleet of F-35 Joint Strike Fighter jets is expected to return to regular flight operations at Eglin Air Force Base in Florida after being grounded because of a fire this week.

All F-35 flight operations for the Air Force at the base had been temporarily suspended as the military investigated the incident. A spokesman at the base said flight operations were expected to resume Wednesday.

Early Monday, one of the radar-evading, supersonic fighter jets caught fire before takeoff. The pilot left the aircraft uninjured, officials said.

The aircraft was preparing to take off on a training mission but aborted when flames appeared in the rear of the aircraft. Emergency responders then extinguished the fire with foam, according to an Air Force statement.

"The pilot followed the appropriate procedures which allowed for the safe abort of the mission, engine shutdown, and egress," Navy Capt. Paul Haas, 33rd Fighter Wing vice commander, said in a statement. "We take all ground emergencies seriously."

An Air Force safety board is expected to begin investigating the incident to determine the cause.

It's the latest setback for the F-35, a nearly $400 billion weapons program under development for more than a decade but billions of dollars over budget and years behind schedule. The per-plane cost estimates have gone from $78 million in 2001 to $135 million today, according to the Government Accountability Office.

Testing the F-35 is key to the Pentagon's ultimate plan to build 2,457 of the planes. The Joint Strike Fighter program centered around a plan to develop one basic fighter plane that could - with a few manufacturing tweaks - be used by the Air Force, Navy and Marine Corps.

The idea is that it can take off and land on runways and aircraft carriers, as well as hover like a helicopter. No one stealthy fighter aircraft has had all these capabilities. From an engineering standpoint, it's a challenging task for plane maker Lockheed Martin Corp. because the requirements of the different services vary so much.

It still has no mission that it can perform half as well as existing aircraft, but when did they ever let that stop them.