As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: DIRTY SOCK ODOR FROM PACKS W/APU ON DURING GROUND OPS/TAXI OUT AND ON DESCENT W/APU OFF. IN IMC ODOR PRESENT THROUGHOUT AIRCRAFT, DISSIPATED SHORTLY AFTER TAKEOFF WITHOUT CREW ACTION. MAINTENANCE REPLACED L /H PACK HEAT EXCHANGER IAW J/C 72C00021005.