What happened
During the initial climb phase, the flight crew encountered an unexpected loss of engine power. This occurred as the aircraft was ascending through an altitude of approximately 200 feet above ground level, shortly after departing the runway. Despite immediate efforts to manage the situation and attempt a return to the airfield, the aircraft lacked sufficient altitude and thrust to complete the maneuver.
The aircraft subsequently impacted trees and the terrain in close proximity to the runway environment. The force of the collision brought the aircraft to a stop adjacent to the paved surface. There were no reports of structural breakup prior to impact, and the sequence of events was driven entirely by the mechanical failure during the critical low-altitude phase of flight.
The investigation
A thorough review of the aircraft's maintenance history revealed significant discrepancies regarding the engine's fuel system components. Records indicated that an incorrect model carburetor had been installed on the engine, which was not compatible with its specific requirements. Prior to the accident, the engine had been operating with a rich fuel mixture due to this installation error. Maintenance work had previously been attempted on the carburetor in an effort to correct the rich mixture condition, but the underlying issue persisted.
Post-accident examination of the installed carburetor provided definitive evidence of the mechanical faults. The mixture control arm was found to be wired in a fixed position, holding it at 40 to 50 percent of its travel range between lean and rich settings. This improper configuration prevented normal fuel-air ratio adjustments. Additionally, the fuel shutoff needle valve exhibited excessive wear. This wear caused the valve to fail to seat properly on occasion, leading to intermittent fuel delivery issues or leakage that contributed to the power loss.
No other evidence of engine malfunction was found during the inspection. The investigation concluded that the primary mechanical failures were limited to the carburetor assembly and its installation errors.