A squadron of F-15 fighter jets based at RAF Lakenheath in Suffolk have been grounded "indefinitely" after flaws have been found in some aircraft.
The planes were originally grounded in November after a crash of a Missouri Air National Guard F-15C.
Early findings indicate a possible structural failure and other older planes were found to have flaws.
A US Air Force spokeswoman said training flights had been hit. Pilots are using flight simulators.
One theory is the damage has been caused by the intense stress placed on the warplanes as they manoeuvre at high-speed, the BBC has been told.
The latest ban is described as "indefinite".