20180811010969A

The aircraft departed keul, caldwell, id on the morning of aug 11, 2018 with the airman and passenger. The aircraft flew to kbke, Baker City Oregon. According to witness statements that aircraft flew over kbke at approximately 10: 15AM PDT heading south with the landing gear extended at approximately 600FT AGL. The remaining witnesses all place the aircraft flying an extended downwind and a base leg approximately 1.3 nautical miles south of the approach end of runway 31 at kbke. Two witnesses stated that the aircraft was making a left hand turn towards the airport.

The accident site was approximately 1.2 nautical miles to the south west of the approach end of runway 31.

All indications are that the aircraft accident was a result of a stall/spin at a low altitude on the base leg to runway 31 at kbke.

The aircraft hit the ground at a near vertical angle. The aircraft was mostly intact but sustained crushing damage to the engine, fuselage, and wing leading edges. The left hand wingtip was towards the north and the right hand wing tip was to the south with the remains of the cabin and engine pointing to the east. The aft fuselage was damaged just aft of the aft bulkhead with crushing and the tail section bending to the right side, typical damage associated with a near vertical impact. The tail section, rudder and elevator were undamaged and control continuity was established to the center fuselage.

Evaluation of the system component indicate that the aircraft was configured with the flaps in the full extended position, the landing gear down and locked and the horizontal stabilizer trimmed full nose up.

The flap position was determined by the ½ inch of exposed threads on the electric flap actuator. Mooney aircraft indicated this is the actuator position for flaps full down.

The gear was determined to be down and locked at the accident site by the landing gear actuator jack screw was fully retracted, indicating the gear would be fully extended. The right hand main gear appears to down and locked but damaged and the aft gear leg attach point was pushed through the upper wing skin. The left hand gear was partially collapsed and damaged and the aft gear leg attach point was pushed through the upper wing skin.

The nose gear was unobservable due to damage.

Both wing fuel tanks were ruptured due to the impact but the smell of avgas was present at the scene. Both wing tank skins were torn away from the spar and ribs, peeling from the bottom forward towards the crushed leading edges indicating a fuel in the tanks at impact.

The propeller was separated from the aircraft and still attached to the crank shaft flange. Turf had been sliced and thrown away from the propeller impact site and the propeller had screwed into the ground, indicating the propeller was rotating and the engine had power at impact.

Found engine was rotating freely, there was small amounts of fuel in the fuel pump and flow divider with no evidence of failure in either. Both magnetos rotated freely and showed no signs of failure and produced ample spark when tested.

The vacuum pump was still attached to the engine mounting pad. When removed it was noted that the plastic drive coupling had sheared. The sheared surfaces exhibited a spiral scar at the core, with smear damage to the outer radius. There was a small amount of oil within the cavity and only a small portion of the rotor was wet with oil. This is possibly oil leaking into the pump after the accident. The rotor was fractured in multiple locations. The pump blades were intact and showed no signs of damage. This possibly indicates that the pump was not rotating at impact.

After a thorough evaluation of the aircraft and engine. No mechanical anomalies were found. All systems required for flight appear to be operational at this time.

It appears that the airman was flying at a low altitude and configured to final approach while on the base leg for runway 31 at kbke. The aircraft entered a stall / spin