What was found
F/A REPORTED SMOKE IN CABIN IMMEDIATELY AFTER T/O. SMOKE DISAPPEARED AFTER POWER WAS REDUCED. RTN TO CVG FOR IMMEDIATE LANDING. BOTH REAR LAV SMOKE DETECTORS ACTIVATED. REMOVED LT ACM DUCTING AND FOUND OIL RESIDUE. SUSPECT LT ACM LEAKING. ACM P/N219001545. REINSTALLED ACM DUCTING. FWD LT A/C PACK TO MCO AND PLAC PER MEL 21-00-01A. SENSE LINE DISCONNECTED AT FLOW CONTROL VLV. REPLACED COALESCER BAGS AFTER DUCT BURNOUT PER MM. OK FOR SERVICE.