What happened
The pilot, holding a private certificate, was conducting a solo instructional flight when the engine suddenly lost power. At the time of the failure, the aircraft was operating at approximately 800 feet above ground level while the pilot was practicing S-turns. The pilot immediately initiated the standard emergency procedure for an engine failure in flight. However, despite these efforts, the engine would not restart.
With no option to return to the departure airport, the pilot selected a nearby road situated atop a dyke as a forced landing site. During the approach and touchdown, the aircraft struck a gouge in the road surface. This impact caused the aircraft to skid off the paved surface and descend down an embankment.
The investigation
A thorough examination of the wreckage was conducted to determine the cause of the power loss. Investigators found no evidence of mechanical malfunction or preimpact failures within the engine or airframe components. The physical condition of the aircraft parts suggested that the engine failure was not caused by a structural breakage or internal component failure detectable post-crash.
Findings
Environmental conditions played a significant role in the incident. At the time of the accident, the ambient temperature was 88 degrees Fahrenheit with a dew point of 72 degrees Fahrenheit. These specific meteorological values indicate high humidity levels. According to standard icing probability charts, these conditions were conducive to visible induction icing. Such icing is particularly likely during phases of flight involving idle or cruise power settings, which aligns with the maneuvers being practiced.
The combination of high humidity and engine operating parameters created an environment where ice could accumulate in the induction system, restricting airflow and causing the engine to stop. The pilot's inability to restart the engine was consistent with this type of failure mode rather than a fuel exhaustion or electrical issue.
Safety message
Pilots operating aircraft equipped with carburetors or induction systems should be aware that high humidity conditions can lead to visible induction icing even when temperatures are well above freezing. This risk is heightened during low-power settings such as cruise or idle. Regular use of carburetor heat and awareness of weather patterns are essential preventive measures.