More than 70 F-15 fighter jets have been grounded at RAF Lakenheath air base in Suffolk while an investigation takes place into a crash in the USA.
The US Air Force suspended non-mission flight operations of its F-15 aircraft on Saturday.
It follows the crash of a Missouri Air National Guard F-15C. Early findings indicate a possible structural failure.
The stand down of the fleet was a precautionary safety measure, the US Air Force said in a statement.
It added: "The Air Force will ensure mission requirements are met for worldwide operations normally accomplished by the F-15."