Amid a seeming non-stop barrage of headlines about flybys, test-flights, and aviation drills among America's nuclear-capable bombing fleet, reports that the Air Force has grounded its entire fleet of B-1B Lancer bombers due to safety concerns. reported that the stand-down is a direct result of a May 1 incident when a B-1 crew in Texas tried to manually eject from the plane, but the seat didn’t blow (and at speeds of over 900 miles per hour, that could be a problem), forcing them to make an emergency landing instead. No one was hurt during the incident.

In a statement Friday, the Air Force said:

“During the safety investigation process following an emergency landing of a B-1B in Midland, Texas, an issue with ejection seat components was discovered that necessitated the stand-down. As issues are resolved aircraft will return to flight,” Air Force Global Strike Command said in a statement.

“The Safety Investigation Board is ongoing,” the Air Force continued.

“The SIB’s purpose is to prevent future mishaps or losses and is comprised of experts who investigate the incident and recommend corrective actions. The safety of airmen is the command’s top priority. The Air Force takes safety incidents seriously and works diligently to identify and correct potential causes.”

The B-1B in April returned back to the Middle East for the first time in nearly two-and-a-half years to take over strike missions from B-52 Stratofortress bombers.

And in case you were wondering who will be on the hook for this mass grounding - simple  - Boeing, which manufactures the bombers at a cost of $317 million each.