As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW - FLT 1542 - JUST AFTER LIFTOFF, FLIGHT ATTENDANT REPORTED SMOKE IN CABIN. OUTFLOW VALVE CYCLED, AND THROTTLES BEGAN TO CYCLE ALMOST AS IF INITIATION RETURNED AND LANDED DFW WITHOUT INCIDENT. OIL LEAKING INTO PACK SYSTEM FROM AUXILIARY POWER UNIT. REPLACED AUXILIARY POWER UNIT. SYSTEM GROUND CHECK NORMAL OPERATION. (M)