What happened
During the initial climb phase following takeoff, the aircraft experienced a sudden loss of power in the left engine. This event occurred shortly after the landing gear was fully retracted into the fuselage. The pilot reported that the sensation of power loss coincided precisely with the moment he toggled the landing lights off.
At the time of the incident, the manifold pressure gauge for the left engine indicated 25 inches of mercury. Based on this reading, the pilot believed the engine was still generating some thrust and therefore did not feather the propeller. Following the power loss, the aircraft turned toward a heading of approximately 035 degrees. Unable to maintain altitude, the aircraft descended into a wooded area characterized by rising hills surrounding the departure airport.
The investigation
A thorough examination of the accident site and the wreckage provided critical insights into the sequence of events. Investigators noted that the terrain was heavily forested with significant elevation changes, which likely contributed to the severity of the impact.
Mechanical inspection of the cockpit controls revealed a crucial discrepancy in switch positions. The magnetos for the left engine, which are physically located immediately above the landing light switches, were found in the 'OFF' position. Simultaneously, the landing light switches themselves were in the 'ON' position. This configuration suggested that the pilot may have intended to turn off the lights but inadvertently switched off the magneto instead.
Findings
The investigation uncovered two significant operational violations prior to the flight. The aircraft was loaded at or above its maximum gross weight limit, which severely degraded climb performance. Furthermore, the center of gravity was positioned aft of the rear allowable limit, creating a highly unstable configuration that made maintaining control and altitude difficult.
The combination of an overloaded aircraft with an aft center of gravity meant that any loss of engine power would be catastrophic during the critical takeoff phase. The misalignment of the magnetos effectively killed the left engine at a low altitude where recovery was impossible. These factors collectively led to the inability to clear the terrain.
Safety message
Pilots must exercise extreme caution when operating switches that are physically adjacent to one another, particularly during high-workload phases like takeoff. Additionally, ensuring the aircraft is within its weight and center of gravity limits is essential for maintaining adequate performance margins.