What happened
On July 26, 2003, a Cessna 150K, registration HB-CUA, was conducting a private pleasure flight from Colmar, France, toward Ostend, Belgium. After an initial leg from Speck, Switzerland, the pilot refueled at Colmar and departed at 10:56 local time.
While navigating the Vosges mountains, the pilot entered a valley at 3,500 feet, flying beneath a cloud layer. Upon reaching a second ridge line, the pilot observed that the peaks were obscured by clouds, making the path impassable. To avoid the clouds, the pilot descended to 3,000 feet and began a right-hand turn with an estimated bank angle of 30° to 45°. During this maneuver, the aircraft's stall warning activated. Despite applying full power and reducing the pitch, the aircraft entered a stall and struck the tops of trees approximately 15 meters high. The impact caused the tail section to become entangled in the trees at an altitude of roughly seven meters, while the forward section of the aircraft struck the ground.
The investigation
The investigation focused on the pilot's decision-making and the prevailing meteorological conditions at the time of the accident. Investigators examined the pilot's reliance on weather forecasts obtained the previous day and on the morning of the flight via telephone and the internet. It was noted that the pilot did not seek updated weather information during the stop in Colmar. Local testimony also indicated that heavy rain had occurred during the morning, leaving the mountain passes and peaks obscured by clouds shortly before the accident.
Findings
- The primary cause of the accident was a stall during a turn while attempting to maneuver within a valley.
- The pilot made a late decision to perform a turnaround.
- The pilot continued the flight at a very low altitude despite encountering unfavorable weather.
- The aircraft sustained significant damage, resulting in the destruction of the Cessessna 150K.
- There was one minor injury involving a passenger, while the pilot was uninjured.