The entire U.S. fleet of B-1B Lancer bombers has been grounded by the U.S. Air Force (USAF) after inspectors discovered a possible defect in the aircraft‘s drogue parachute, which, according to a report from The Drive, is a component of the aircraft’s ejection seat. The drogue suit ensures the ejection seat remains level and oriented properly when the occupant activates the emergency egress system. The B-1’s ejection seat is manufactured by United Technologies Corporation, which also supplies ejection seats for the majority of the USAF’s aircraft.

“During a routine inspection of the B-1B drogue chute system, potentially fleet-wide issues were identified with the rigging of the drogue chute,” said a spokesperson from the USAF’s Global Strike Command, located at Barksdale Air Force Base in northwest Louisiana. “It appears to be a procedural issue and is unrelated to the previous problem with egress system components. As a precautionary measure, the commander directed a holistic inspection of the entire egress system. The safety stand-down will afford maintenance and aircrew flight equipment technicians the necessary time to thoroughly inspect each aircraft. As these inspections are completed and any issues are resolved, aircraft will return to flight.”

The USAF also stated, “The safety of airmen is the command’s top priority and this precautionary step will enable the command to correct any potential issues.”

This is not the first time issues with the B-1’s emergency egress system have kept the fleet on the ground. In June of last year, the USAF instituted a safety stand-down to repair an issue with the B-1’s ejection seats. The issue was identified after an in-flight emergency left a B-1 crew member strapped to a malfunctioning seat, according to The Drive. The previous stand-down lasted nearly a month.

Currently, the USAF operates 62 Lancers, which have seen extensive service throughout the entire Global War on Terrorism. However, according to a report from Fox News, none of the aircraft are currently deployed to any war zones. It is not clear at this time if any other defects have been found since the stand-down began on Thursday.

The discovery of the drogue chute defect underscores the importance of the USAF’s maintainer force. These crucial positions are filled primarily by enlisted airmen, but the Air Force has had trouble staffing enough qualified personnel in these roles. To combat the shortage and help retain senior maintainers who are necessary to train the new service members, the USAF has implemented several bonus programs.