As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) UPON ARRIVAL AT GATE WHEN APU AIR SELECTED 'ON', CABIN AND COCKPIT FILLED WITH BLUE SMOKE. CAUSED BY THE INGESTION OF HYDRAULIC OIL IN THE APU AIR INTAKE. SOURCE OF FLUID CAME FROM RT WHEEL WELL. MAINTENANCE FOUND 2 (B) NUTS LOOSE ON ONE HYDRAULIC LINE NEAR RT HYDRAULIC RESERVOIR. NUTS TIGHTENED AND SYSTEM CHECKED SERVICEABLE.