What was found
AFTER TAKEOFF (APPROX 60 SECOND) ALL 3 LAV SMOKE DETECTORS SOUNDED FA'S AND PAX'S REPORTED SMOKE SMELL AND HAZE EMERG RETURN TO ATL. FOUND OIL CONTAMINATION IN APU INLET. LK CKD APU. FOUND B-NUT LEAKING ON OIL LINE AFT FILTER MODULE. TIGHTENED SAME. LK CK GOOD. REMOVED LOWER DOOR ASSY CLEANED INLET AND DOOR ASSY. REPLACED SEPARATOR BAGS AND CLEANED OIL FROM DUCTS. PERFORMED FULL DUCT BURNOUT OPN 5089. RAN ENGS TO T/O PWR SEVERAL TIMES. ALL CK GOOD, BORO OF 6TH 7TH STG COMPRESSOR ON BOTH ENGS CKD GOOD. NO OIL PRESENT.