Air Force orders Boeing F-15 fighter jets grounded

WASHINGTON — The U.S. Air Force has grounded its entire fleet of Boeing F-15s, the service's premier fighter aircraft, after one of the planes disintegrated over eastern Missouri during a training mission, raising the possibility of a fatal flaw in the aging fighters' fuselage that could keep it out of the skies for months.

Gen. T. Michael "Buzz" Moseley, the Air Force chief of staff, ordered the grounding after initial reports showed the Missouri Air National Guard fighter plane broke apart Friday in midair during a simulated dogfight.

Although the 688 F-15s in the Air Force's arsenal gradually are being replaced by a new generation of aircraft — Lockheed Martin's F-22 — they remain the nation's most sophisticated front-line fighters. U.S. officials said the F-15s are used heavily for protecting the continental U.S. from terrorist attack, as well as for combat missions in Iraq and Afghanistan.

Lt. Gen. Gary L. North, the Air Force officer in charge of military aircraft in the Mideast, said he would be able to fill the gap with other fighters and bombers. But another Air Force official said the F-15 grounding will have a "significant impact" on operations in Iraq and Afghanistan.

Boeing spokeswoman Patricia Frost said the Chicago-based company was cooperating with the Air Force but could not comment because of the pending investigation.

The health of the F-15 fleet has long been a concern for Air Force brass, who repeatedly have warned that the two-engine fighter had exceeded its expected life span and was straining under the workload imposed by the counterterrorism duty.

The F-15 that crashed Friday was 27 years old. The pilot survived. Of the five versions of the F-15 used by the Air Force, four versions average between 24 and 30 years of age. The F-15E, the newest version, is only 15 ½ years old but has been grounded along with the other versions because it has a similar airframe.

Loren Thompson, a military analyst with the Lexington Institute who has consulted for aircraft manufacturers, said the accident probably was caused by metal fatigue, corrosion or faulty maintenance.

If it can be blamed on maintenance problems or corrosion, Thompson said, the F-15 fleet could be returned to flight relatively quickly.

But if the crash was the result of metal fatigue, it could lead to a much more extended grounding, as it would suggest that time and intense use of the aircraft since the Sept. 11, 2001, attacks have caught up with the aging fighter.