Accident Sequence
The airplane collided with obstructions following a loss of power in one engine during a missed approach. After the collision sequence, the airplane came to rest upright about 500 feet from the approach end of the runway and was destroyed in a post-impact ground fire.
The pilot informed a responding sheriff's deputy and a Federal Aviation Administration (FAA) inspector that he conducted an ILS approach to land and initiated a missed approach. When he added power, the left engine sputtered and the airplane veered left. He activated the fuel boost pump, but the airplane contacted obstructions and crashed.
A responding sheriff's deputy observed the accident. He heard an engine producing unusual sounds, reporting that the engine "seemed to get quiet and then revved higher as if to climb." He looked toward the sound and saw a series of blue flashes followed by an orange fireball. The deputy noted dense fog in the area at the time.
Wreckage Examination
Examination of the wreckage revealed that neither engine's propeller was feathered, the landing gear was down, and the flaps were extended to 10 degrees. No discrepancies were noted during the airframe examination. The engine examination found no mechanical anomalies with either engine that would have precluded normal operation.
Performance Analysis
According to the operator's records, the airplane's gross takeoff weight at departure from Ukiah was approximately 5,909 pounds. The Pilot Operating Handbook (POH) specifies the following items for the single-engine go-around checklist: throttle full forward; wing flaps up; when positive climb rate is achieved, gear up; and ensure the inoperative engine is feathered.
For a gross weight of 5,900 pounds and the existing atmospheric conditions, the single-engine climb performance chart indicated an expected positive rate of climb of 500 feet per minute if the airplane was correctly configured. The chart also listed subtractions from that performance for specific conditions: −400 fpm for a windmilling inoperative engine; −350 fpm for landing gear down; and −200 fpm for flaps extended to 15 degrees.
With the airplane not configured correctly for the single-engine missed approach (propellers not feathered, gear down, flaps at 10 degrees), the net climb performance would be a negative 400 feet per minute.
Weather and Regulatory Context
At the time of the accident, the airport weather was reported as 100 feet overcast and 1/4-mile visibility in fog. The landing minimums for the ILS approach are 200 feet and 1/2-mile. According to 14 CFR 135.224, a pilot cannot initiate an approach if weather is below landing minimums when the approach is started outside the final approach fix; the pilot may continue the landing if already established on the approach and the airport goes below minimums. The operator's FAA-approved operating specifications did not authorize lower-than-standard landing minimums.