Incident Overview
During the descent phase to a high-altitude airport, the left engine began to surge. The pilot attempted to resolve the issue by resetting the power and mixture controls, but these actions did not stop the surging.
Approach and Final Descent
While on the base leg to the runway, the pilot turned on both fuel pumps, an action contrary to the procedures specified in the Pilot Operating Handbook. As the airplane progressed to the final approach, the left engine started to vibrate violently. The pilot then applied power to both engines but found that no power was available.
Collision and Damage
The airplane's altitude was insufficient to reach the runway. It undershot the intended landing area and collided with a hole approximately 3 feet deep. The impact caused the left main landing gear to collapse.
Post-Accident Engine Tests
Subsequent engine run tests were conducted. The initial surging could not be replicated due to limitations of the test club propeller. However, when the mixture was set to rich and both boost pumps were turned to high, both engines quit.