As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: AIR CONDITIONING ODOR NOTED ON GROUND AFTER FIRST ENGINE START WITH BLEED SUPPLIED BY APU. MUSTY/MECHANICAL/SEWER SMELL DETECTEDPRIMARILY ON THE FLIGHT DECK. ODOR SEEMED TO DISSIPATE AFTER SECOND ENGINE START, BUT DETECTED AGAIN ON DESCENT, BOTH ON FLIGHTDECK AND MID CABIN. NO IRRITATION OF EYES OR AIRWAYS WAS NOTED. (OPEN)