All "non-mission critical" flights were suspended Saturday, a day after a Missouri Air National Guard jet crashed in a wooded area, the Air Force said in a release dated Sunday.
The pilot, who ejected, was released from a hospital Saturday after being treated for a dislocated shoulder, broken arm and minor cuts; no one else was hurt.
It was unclear which flights were considered non-mission critical. Calls seeking additional Air Force comment were not returned.
The Air Force described the grounding as a precaution, but said preliminary findings indicate the aircraft may have suffered a structural failure. It did not elaborate, but said the crash remains under investigation.
The Air Force said more than 700 F-15s are in its worldwide inventory, and said it will ensure that mission requirements are met for operations normally accomplished by the fighter jet. F-15s fly from bases in the U.S., England, Japan and the Middle East.
The Air Force has been using the F-15 since the mid-1970s. The fleet is currently being replaced by the F-22 Raptor, but F-15s still make up a significant percentage of its fighter jets.
Col. Robert Leeker, commander of the 131st Fighter Wing, said Friday the plane had been among four planes that split into pairs and engaged in one-on-one training fights in which speeds of 400 to 450 mph are typical. There was no contact between the plane and its partner in the mock fight.
An Air Force investigative report is due in 60 days.
Another Missouri Air National Guard fighter, an F-15D, crashed in May after taking off from Lambert Airport in St. Louis. The pilot ejected and suffered minor injuries; an Air Force report last month concluded that a jammed cable caused the crash.
The F-15 was originally manufactured by St. Louis-based McDonnell-Douglas, which was purchased by Boeing Co. about a decade ago. A Boeing spokesman did not return a phone call seeking comment.