The safety stand-down, ordered Thursday, follows an investigation into an emergency landing made at Midland, Texas on May 1.

Four crewmembers had to land their bomber after some sort of "inflight emergency," officials said. No one was harmed.

During the investigation into that incident, "an issue with ejection seat components was discovered that necessitated the stand-down. As these issues are resolved, aircraft will return to flight," the Air Force said in a statement.

The B-1B Lancer is a supersonic bomber that can carry the heaviest conventional payload of all the US military's planes.

It has wings that can adjust according to its speed and cargo. Though it was originally designed as a nuclear bomber it can no longer carry such weapons.