The US Air Force has grounded its entire fleet of F-15 fighter jets after one of them crashed on a training mission in Missouri last week.
Use of the planes will be restricted until a possible structural failure in the aircraft has been investigated, an air force spokesman said.
The US has about 700 F-15s in service, including a number in Afghanistan.
F-15s have had several accidents this year, although the current suspension is linked only to last week's crash.
Preliminary inquiries suggest that the F-15 may have been affected by a mechanical failure.
The plane belonged to the Missouri Air National Guard and was being used in a training exercise when it crashed near the city of Salem, Missouri.
The pilot ejected from the plane and suffered a broken arm and minor cuts and bruises.
Orders to ground an entire fleet of planes are not common: Air Force spokeswoman Jennifer Bently said that she was "unsure" when the step had last been taken.
Although the decision to ground the F-15s was based solely on the Missouri crash, the jets have been involved in three other accidents in recent months.
F-15s have been a mainstay of the US air force since 1975, but the Air Force stopped buying them in 2004, intending to replace them gradually with the more up-to-date F-22 Raptor, made by Lockheed Martin.
Boeing - the manufacturer of the F-15 - is still producing them for other customers. ( BBC )