Beech V35B N65Y accident near Livermore, California

Probable cause

The pilot’s inadvertent use of the mixture control instead of the throttle, which resulted in fuel starvation and the subsequent loss of engine power.

NTSB analysis

The pilot planned on remaining in the traffic pattern for night flight. Shortly after takeoff, while on the upwind leg of the traffic pattern, the cabin door opened; the pilot stated that he slowed the airplane by using the throttle. He added that it was dark and that he could not see the instruments, but he could see the engine control knobs. The pilot realized the airplane was descending toward a building when he heard the tower controller say “climb, climb, climb.” The pilot then “pushed the throttle in.” The airplane continued to descend and impacted a building. Additionally, the pilot added that due to the dark conditions, he may have mistakenly pulled the mixture control knob to slow the airplane down instead of using the throttle.

Postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. Continuity of the throttle, propeller, and mixture controls was established from the cockpit to their respective control arms. Examination of the throttle revealed the throttle knob was about 1 inch from full forward, the mixture control was about 2 inches from full forward, and the propeller controller lever was about ½ inch from full forward. The pilot likely inadvertently manipulated the mixture to a lean position instead of the pulling back on the throttle, which resulted in the reduction of engine power.

Text from the NTSB. Open the NTSB docket for WPR23LA077 for the full record.