What happened
On October 31, 1997, a Cherry BX 2 aircraft, registration PH-LVK, was conducting a local recreational flight from Midden-Zeeland airfield. During the flight, the aircraft was observed at various low altitudes over several locations, including Nieuwerkerk and Serooskerke. Witnesses noted the aircraft flying at very low altitudes with a constant, low engine RPM.
As the aircraft approached the residential area of Middelburg, witnesses reported hearing the engine sputter and struggle, describing a sound similar to a "drowning" engine. The aircraft was seen flying low over a large apartment building, performing a slight right turn. During this maneuver, the aircraft struck a tree, lost significant altitude, and its propeller impacted the facade of a house. The aircraft ultimately came to rest on its back in a street, resulting in the deaths of both occupants.
The investigation
The investigation focused on the mechanical condition of the engine and the environmental factors present during the flight. Investigators reconstructed the aircraft from wreckage found at the scene. While some control components showed signs of overload, these were determined to be results of the impact rather than a pre-existing failure.
Technical analysis of the engine revealed that the spark plugs and intake/exhaust ports were very oily. Evidence suggested the aircraft was likely using automotive gasoline (Mogas) rather than aviation gasoline, as the owner frequently refilled the tanks using jerrycans. The investigation also examined the weather conditions, noting a temperature range of 7°C to 11°C and relatively high humidity (45% to 60%) at the flight altitudes.
Findings
- The aircraft was operating at a very low altitude and low power setting for a significant portion of the flight.
- The use of automotive gasoline likely increased the risk of ice formation, as such fuel is more volatile and may contain higher water content.
- The specific combination of the Continental C-90 engine, the prevailing temperature and humidity, and the low power setting created a high risk for carburetor icing.
- The low flight altitude prevented the crew from attempting an emergency landing outside of the residential area.