As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT NR 3055 - ORF-DCA - DURING PREFLIGHT CHECKS, THE CABIN FILLED WITH SMOKE. THE LEFT PACK WENT RED LINE AND AUTO SHUTOFF DID NOT WORK. FOUND AIR CYCLE MACHINE SEIZED. REMOVED AND REPLACED THE LEFT AIR CYCLE MACHINE AND THE LEFT DUCT TEMP SWITCH. REFERENCE HNAA9690514.