Israel and Saudi Arabia have been operating F-15s since the 1980s.
Neither country has reported major difficulties.
The threat to the F-15, manufactured by Boeing, was determined in wake
of a crash of an F-15C Eagle on Nov. 2, 2007. An air force investigation
determined that the accident stemmed from a defect in the upper right
longeron, one of four metal beams that help hold the cockpit to the main
fuselage.
Corley said nine other F-15s were found to have similar cracks in their
longerons. He said the problem appeared to be endemic among F-15A through D
models built between 1978 and 1985.
"We're going over each and every aircraft to make a determination,"
Corley said in a Jan. 10 briefing. "We will take some F-15s out of the
inventory. It just doesn't make sense to spend the time and money if it
won't be worth it for some aircraft."
Col. William Wignall, the head of the accident investigation, said the
longeron in the F-15C cracked under the stress of a turn. Wignall said the
longeron was not designed according to specification.
Since then, the air force has grounded its F-15 fleet, and air defense
operations were assumed by F-16 multi-role fighters. As of Jan. 9, the
military approved the return to service of 260 F-15A through D models — or
60 percent of the fleet — without flight restrictions.
"We've had great involvement from Boeing during the investigation,"
Wignall said. "In fact, they're the ones who determined the longeron was the
problem. This was then confirmed by the Air Force Research Laboratory."
