As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ACFT WAS COMING OUT OF ANNUAL INSPECTION. LOW ALTITUDE FUNCTIONAL FLIGHT CHECK INDICATED NO ABNORMALITIES. HIGH ALTITUDE FUNCTIONAL FLIGHT CHECK INDICATED SMOKING EXHAUST PIPE AND LOSS OF TURBO SYSTEM. DECOWLING SHOWED OIL SPRAY. TRACED BACK TO FITTING ON SCAVENGE PUMP. FURTHER INSPECTION REVEALED FITTING WAS NOT TIGHTENED FOLLOWING REINSTALLATION FOLLOWING STARTER ADAPTER O/H.