As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GNDED. ON GND WITH APU BLEED ON, SMELL OF DIRTY SOCKS. AFTER APU SHUTDOWN & ONCE WE REACHED CRUISE ALTITUDE, SMELL DISSIPATED & WENT AWAY. FOUND THE APU LEAKING OIL AT THE APU OIL COOLER, THE APU OIL COOLER FAN SATURATED WITH OIL & REPLACED THEM IAW AMM 49-91-44 & 49-52-51. IN ADDITION TASK CARDS 26L00021001, 26L00021002 & 26L00021004 WERE ACCOMPLISHED. A SATISFACTORY LEAK & OPERATIONAL CHECK WAS ACCOMPLISHED WITH NO ODORS BEING NOTED. SEE AALA 201603189008 FOR ADDITIONAL PART INFORMATION.