What happened
The pilot departed with all fuel tanks full but managed the fuel system by utilizing the main tanks until they were approximately half full. He then switched the selection to the tip tanks and continued flying until those tanks were completely emptied. Based on experience from a previous flight, he anticipated that the left tip tank would empty approximately eight minutes before the right one.
When the aircraft was at approximately 5,000 feet above ground level, the left tip tank ran dry. At this moment, the left engine lost fuel pressure and power. The pilot immediately switched the left fuel selector back to the left main tank, but engine power was not restored. During the attempt to restart the left engine, the aircraft encountered a strong downdraft and began losing altitude rapidly. The left propeller continued to windmill.
The pilot elected to land on a nearby road. He stated that he knew the right tip tank was also due to run dry and switched the right fuel selector to the right main tank. However, the right engine quit at an altitude of 100 to 150 feet above ground level. A passenger reported that the right engine stopped five to ten minutes after the left engine. The pilot then attempted to land in a field, but the aircraft struck power lines and crashed.
The investigation
Examination of the wreckage revealed no pre-impact mechanical failures or anomalies that would have prevented normal operation. The fuel management sequence described by the pilot was consistent with the physical evidence. It is noted that restarting an engine after it has stopped due to fuel starvation typically requires considerably more time than a standard restart procedure.
Findings
The primary factor in this accident was fuel exhaustion of both engines. The pilot's decision to rely on tip tanks without adequate reserve, combined with the extended time required to restart engines after fuel starvation, led to an inability to maintain altitude. The encounter with a strong downdraft further accelerated the loss of height during the critical engine restart phase.
Safety message
Pilots should be aware that restarting an engine after it has stopped due to fuel starvation can take significantly longer than normal procedures allow. Adequate fuel reserves must be maintained, particularly when operating in conditions where immediate landing options are limited or weather conditions may exacerbate altitude loss.