As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CAPTAIN'S OXYGEN MASK MICROPHONE IS INOPERATIVE. CREW COMMENTS: CAPT SWAPPED MASK WITH 1 OBS MASK--NO CHANGE PROBLEM IN LOWER BOX. SWAPPED FIRST OBSERVERS MASK BOX ASSY WITH CAPTS MASK BOX ASSY. OPS CHECK OF CAPT'S OXY MASK MIC GOOD. FIRST OBSERVERS SEAT DEFERRED.