As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: ON THE TAKEOFF ROLL A SOUR MUSTY ODOR OCCURRED. UPON CLIMBOUT THE SMELL COMPLETELY DISSIPATED. THEN ON APPROACH AT APPROXIMATELY 5000FT THE ODOR CAME BACK. IN RIGHT HAND PACK BAY, FOUND ORANGE FLEX DUCT BLOWN. REMOVE AND REPLACED THE FLEX DUCT. OPERTIONAL AND LEAK CHECK GOOD. PER AMM 21-51-04.