What happened
On 16 October 2011, a Piper PA-18-95 Super Cub, registration OO-KKK, departed from the airfield of Verviers/Theux for a local photography flight. The crew, consisting of a pilot and a passenger, were attempting to capture images of another aircraft in flight.
During the departure from runway 06, the aircraft exhibited an unusually high pitch angle, with the tail wheel remaining on the ground at the moment of lift-off. As the aircraft climbed, it struggled to gain sufficient airspeed and altitude. Shortly after crossing a nearby highway, the aircraft entered a left turn, followed by a roll to the right and a subsequent descent into a field. The impact resulted in two fatalities and the total destruction of the aircraft.
The investigation
The AAIU(Be) examined the wreckage, maintenance records, and flight parameters. The investigation focused on the aircraft's configuration during the take-off roll and the aerodynamic behavior of the plane during the initial climb. Investigators analyzed the available runway length, the aircraft's weight and balance, and the position of the stabilizer trim. The investigation also considered environmental factors, such as the presence of high-voltage power lines near the flight path and the impact of the sun's position on the crew's visibility.
Findings
- The aircraft was within its permitted weight and center of gravity limits.
- The engine and airframe showed no signs of mechanical failure or malfunction prior to the accident.
- The aircraft was operating with the stabilizer trim in the full nose-up position.
- The takeoff roll began from the middle of the runway, leaving a distance that was sufficient for the takeoff run but at the very limit for clearing the 50-foot obstacle.
- The pilot's high pitch attitude during lift-off, combined with the extreme trim setting, placed the aircraft in a state of reversed command, making it difficult to maintain a proper climb pitch.
- The aircraft's stall was likely triggered by a climbing turn, which increased the stall speed and contributed to the loss of control.
Safety action
No specific safety recommendations were issued following this investigation.