Engine Problem Grounds B-1Bs

WASHINGTON — The Air Force has grounded its fleet of B-1B strategic bombers after an engine problem similar to one in which an engine dropped off of a bomber in flight, officials said Thursday.

A B-1B on a training flight early Wednesday morning was making practice approaches at Dyess Air Force Base, Tex., when the crew heard a loud bang, Pentagon spokesman Bob Hall said. Ground safety personnel reported a fire in the right inboard engine. The plane made an emergency landing but no one was hurt.

Officials suspect that a problem with the first-stage compressor fan blades was responsible. The same cause is believed to be behind an Oct. 11 incident in which the crew of a plane from McConnell Air Force Base, Kan., heard a similar bang and, after landing, found that the left outboard engine had fallen off.