What happened
The flight was proceeding normally until the pilot initiated a descent from an altitude of 4000 feet toward a planned level-off at 1000 feet. As power was applied to maintain the desired altitude, the engine failed to respond, resulting in a complete loss of thrust. The pilot did not utilize carburetor heat during the initial descent or after the power failure occurred. With no engine power available, the pilot executed a forced landing in an adjacent bean field.
During the approach to the field, the aircraft collided with a wire, which caused significant damage to the right main landing gear. The aircraft touched down and subsequently nosed over. Weather conditions at the time of the incident were clear with a temperature of 75 degrees Fahrenheit and a dew point of 47 degrees Fahrenheit.
The investigation
Following the accident, mechanics performed a post-mishap engine test run to determine if mechanical failure was the root cause. The test results indicated that the engine met normal operational specifications, suggesting that the power loss was not due to internal engine malfunction or mechanical defect.
Findings
The investigation highlighted several critical factors contributing to the accident. The primary issue was the carburetor ice formation, which is a common hazard when operating aircraft in conditions with high humidity and moderate temperatures. The pilot failed to use carburetor heat during the descent, despite the environmental conditions being conducive to ice accumulation.
Additionally, the collision with the wire during the forced landing approach resulted in damage to the right main gear, which contributed to the nose-over upon touchdown. The lack of power management and situational awareness regarding icing risks were central to the outcome.
Safety message
Pilots operating aircraft equipped with carburetors must be vigilant about the risk of carburetor ice, especially during descent phases where power settings are reduced. Carburetor heat should be used proactively in conditions conducive to icing, such as when the temperature is between 20 and 70 degrees Fahrenheit with visible moisture or high humidity. Regular use of carburetor heat can prevent power loss and ensure engine performance remains stable.