As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT LOWER ALTITUDES, PACKS PRODUCE MOLDY ODOR MAKING IT DIFFICULT TO BREATH. THIS OCCURS AT HIGHER POWER SETTINGS. PERFORMED OPEATIONAL CHECK OF LEFT & RIGHT PACKS AT LOW & HIGH TEMPS. ALL CHECKS NORMAL. NO DEFECTS NOTED AT THIS TIME, IAW AMM 21-51-00.