WASHINGTON – The Air Force likely will order dozens of its F-15 fighter jets permanently grounded because of critical structural flaws, significantly reducing the number of planes available to protect the United States, officials said Tuesday.
After one of the fighters broke apart during a simulated dogfight in November, Air Force officials grounded the entire F-15 fleet, nearly 700 planes, fearing such a defect. The newest versions of the fighter jets were allowed to resume flying shortly afterward, but 440 of the older model F-15s have remained out of service.
The Air Force plans to allow about 260 of the remaining grounded planes to return to duty Wednesday. But about 180 will remain idle because of suspected structural flaws.
“Many of them may never fly again,” said a senior Air Force officer. The officer, like others interviewed, spoke on condition of anonymity because results of the investigation are not due to be made public until today.
Long the nation’s most sophisticated front-line fighters, many of the F-15s have been around for 30 years, and the fleet gradually is being replaced. The Air Force still relies on F-15s to protect the continental United States and to fly combat missions abroad. Newer model F-15Es are used in combat in Iraq and Afghanistan and were the first of the planes to resume flying after the mishap in November.
The problems with the F-15, Air Force officials argue, have increased the need to purchase additional F-22s, a swift and stealthy but expensive new fighter plane.
“This is grave,” said a senior Air Force official. “Two hundred of our air superiority aircraft are on the ground, and we are acting like it is business as usual.”
An investigation of the Nov. 2 crash shows the F-15 that broke apart in mid-air had a fault in a crucial support component called a longeron, a structural beam that serves as part of the spine of the aircraft. F-15s have four longerons around the cockpit.
Air Force officials have not yet learned how a defective beam came to be installed in the plane when it was manufactured in 1980. But Air Force officials emphasized that the age of the airframe, combined with the faulty part, put the older F-15s at risk.
“This airplane broke in half because of a fatigue crack,” the officer said.
The Air Force has found cracks in nine of the approximately 180 planes that remain grounded, but it is believed that more than just those nine have faulty structural beams.