As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH - DURING MAINTENANCE INSPECTION MAINTENANCE REPORTED THAT WITH ENGINE ONE BLEED ON, BOTH PACKS FILLED THE CABIN WITH SMOKE. MAINTENANCE PREFORMED PACK SYSTEM OPERATIONAL CHECKS WITH ENGINE 1 BLEED WITH NO DEFECTS FOUND, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.