What happened
During the preflight inspection, the pilot observed that the engine ran roughly on the right magneto but smoothed out as the check continued. After departing the runway with the stall warning horn sounding, the pilot initiated a turn into the wind. However, due to buildings obstructing the intended path, the pilot executed a 360-degree turn instead.
The aircraft failed to gain altitude during this maneuver. In an attempt to recover airspeed, the pilot lowered the nose of the aircraft. Despite these efforts, the aircraft collided with trees and subsequently landed in a creek.
The investigation
The investigation focused on the mechanical condition of the aircraft prior to the flight. The primary finding was the rough running of the engine on the right magneto during preflight, which had temporarily smoothed out. No further mechanical failures were detailed in the source narrative beyond this initial observation and the subsequent aerodynamic stall implied by the warning horn.
Findings
Contributing factors included the engine performance anomaly noted during preflight and the aircraft's inability to climb adequately during the takeoff phase. The stall warning horn indicated that the aircraft was approaching or exceeding its critical angle of attack. The pilot's decision to perform a 360-degree turn in close proximity to obstacles, combined with insufficient climb performance, led directly to the collision.
Safety message
Pilots should ensure engine performance is fully verified during preflight and avoid tight turns at low altitudes if climb performance is questionable. Addressing magneto roughness before departure is critical to preventing in-flight power loss or stall conditions.