The Air Force has ordered the grounding of the F-35A Lightning II stealth fighters at Luke Air Force Base, Arizona after several pilots reported issues with the aircraft’s breathing system that caused symptoms similar to hypoxia.

Fighter Sweep has reported on the issues the US Navy is experiencing with breathing systems in the T-45 and F-18 resulting in flight instructors ‘going on strike’ and refusing to fly until the problems were addressed.

So far, the Air Force’s F-35 problem has occurred only at Luke; other pilots flying the service’s newest fighter plane haven’t reported any incidents, according to the release.