As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED- SMOKE IN CABIN AND COCKPIT, BURNING SMELL. DECLARED EMERGENCY, DONNED OXYGEN MASKS AND PERFORMED EMERGENCY RETURN TO TAOS. CORR ACTION- MX TROUBLESHOT TO BAD ACM AND AFTER OPS TEST OF PACK SYSTEM AFTER MEL APPLIED VERIFIED NO SMOKE OR FUMES PRESENT. MX THEN APPLIED MEL TO PACK 1. SINCE MEL WAS APPLIED AIRCRAFT IMMEDIATELY RELOCATED TO BUR AND MX HAS REPLACED THE ACM AND AIRCRAFT IS AWAITING OPS TEST.