What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) See attached pilot statement (.4) the pilot reported that 2 to 3 minutes after takeoff, the cockpit filled with thick smoke that smelled of burning oil, and the engine oil temperature registered above the upper limit. The pilot turned the airplane back for the departure airport and configured the airplane for landing. No corresponding increase in thrust was realized from increased engine power and propeller RPM adjustments, so the landing gear was raised in an attempt to extend glide performance. The airport could not be reached, and the pilot performed an off-airport landing. Inspection of the airplane's engine revealed an open threaded hole on the right side of the prop governor drive adapter. Further investigation revealed a 90 degree fitting attached to a hose laying on the bottom of the cowling. Visual and tactile inspections of the governor drive adapter housing revealed that threads were still present, but were damaged. The 90 degree fitting was made of steel, and the governor drive adapter of soft aluminum. An FAA airworthiness inspector stated that with the propeller governor oil line disconnected, the oil supply would pump ove rboard and the pilot would lose all control of propeller RPM.
As the FAA filed it
(-23) SEE ATTACHED PILOT STATEMENT (.4) THE PILOT REPORTED THAT 2 TO 3 MINUTES AFTER TAKEOFF, THE COCKPIT FILLED WITH THICK SMOKE THAT SMELLED OF BURNING OIL, AND THE ENGINE OIL TEMPERATURE REGISTERED ABOVE THE UPPER LIMIT. THE PILOT TURNED THE AIRPLANE BACK FOR THE DEPARTURE AIRPORT AND CONFIGURED THE AIRPLANE FOR LANDING. NO CORRESPONDING INCREASE IN THRUST WAS REALIZED FROM INCREASED ENGINE POWER AND PROPELLER RPM ADJUSTMENTS, SO THE LANDING GEAR WAS RAISED IN AN ATTEMPT TO EXTEND GLIDE PERFORMANCE. THE AIRPORT COULD NOT BE REACHED, AND THE PILOT PERFORMED AN OFF-AIRPORT LANDING. INSPECTION OF THE AIRPLANE'S ENGINE REVEALED AN OPEN THREADED HOLE ON THE RIGHT SIDE OF THE PROP GOVERNOR DRIVE ADAPTER. FURTHER INVESTIGATION REVEALED A 90 DEGREE FITTING ATTACHED TO A HOSE LAYING ON THE BOTTOM OF THE COWLING. VISUAL AND TACTILE INSPECTIONS OF THE GOVERNOR DRIVE ADAPTER HOUSING REVEALED THAT THREADS WERE STILL PRESENT, BUT WERE DAMAGED. THE 90 DEGREE FITTING WAS MADE OF STEEL, AND THE GOVERNOR DRIVE ADAPTER OF SOFT ALUMINUM. AN FAA AIRWORTHINESS INSPECTOR STATED THAT WITH THE PROPELLER GOVERNOR OIL LINE DISCONNECTED, THE OIL SUPPLY WOULD PUMP OVE RBOARD AND THE PILOT WOULD LOSE ALL CONTROL OF PROPELLER RPM.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.