What was found
AUS - FLIGHT 1592 - EN ROUTE AUS-ORD, ON TAKEOFF AT AUS A RUBBER / INSULATION / ELECTRICAL ODOR WAS NOTED. IT INCREASED TO A VISIBLE HAZE IN THE CABIN. RETURNED AUS, HAZE DISSIPATED, LANDED AUS WITHOUT INCIDENT. REPLACED APU OIL DRAIN PLUG, LEFT AND RIGHT AUGMENTATION VALVES, AND COALESCERS BAGS. PERFORMED AIRCRAFT PACK BURN OUT. NO ODOR NOTED. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)