What happened
On February 17, 2011, a private Dyn Aero MCR01, registration G-BYEZ, was performing circuit patterns at the Sarlat Domme aerodrome. During the climb, the pilot reached a stabilized speed of 100 mph, but at approximately 400 feet, the stall warning alarm began to sound. Despite increasing power, the alarm continued to trigger intermittently.
Upon reaching 1,500 feet, the pilot decided to terminate the flight and execute a precautionary landing on the paved runway 11. During the final approach, the aircraft was flown with full flaps at an indicated airspeed of 85 mph, which was 15 mph above the manufacturer's recommended speed. The pilot noted a significant floating sensation during the approach. The aircraft touched down before the end of the 745-meter runway. Realizing the aircraft would not stop before the runway terminus, the pilot switched the magnetos to the off position. The aircraft subsequently exited the runway longitudinally and overturned into a ploughed field. The pilot sustained slight injuries, while the aircraft was heavily damaged.
The investigation
The investigation focused on the sequence of events leading to the loss of control and the cause of the stall warning. Following the accident, the pilot disassembled the stall warning sensor to inspect its functionality. The examination revealed that the alarm activation switch was stuck in the "alarm" position, causing the intermittent warnings experienced during the climb.
Findings
- The primary cause of the accident was the decision to continue the landing when the remaining runway distance was insufficient and the approach speed was too high.
- The malfunctioning stall warning alarm likely contributed to the pilot's decision to proceed with the landing rather than performing a go-around.