What was found
EXPERIENCED A SOF EVENT. AIRCRAFT WAS GROUNDED. MAINTENANCE ACCOMPLISHED SOF JC 26L00021001 AND 26L00021002, APU WAS FOUND TO BE SOURCE OF ODOR. FOUND OIL IN INLET AND PLENUM/DIFFUSER WITH NO EXTERNAL OIL LEAKS ON APU, SUSPECTED INTERNAL OIL LEAK IN APU. MAINTENANCE INSPECTED APU NO LEAKS, NO OIL, NO ODOR NOTED AND PERFORMED SATISFACTORY OPERATIONAL CHECK.