What happened
On the morning of November 4, 2007, a DYN'AERO MCR-01 VLA, registration HB-YKL, departed from Bex airfield for a flight intended to demonstrate the aircraft's performance. The flight was being conducted by the owner-pilot with a passenger in the right seat. After climbing to approximately 1,300 feet, the aircraft flew toward Lake Geneva.
During the flight, the aircraft entered a phase of low-speed flight, which transitioned into a series of descending, spinning maneuvers. Witnesses on the water observed the aircraft performing erratic, high-bank turns before entering a near-vertical descent. The aircraft struck the surface of the lake at high speed, approximately 3.5 km south of Montreux. The impact occurred at a depth of 31 meters, and the aircraft was destroyed.
The investigation
Investigators examined the wreckage, the engine, and the flight controls. The investigation established that the engine was producing power at the moment of impact, as evidenced by the breakage of the three propeller blades. While the aircraft was found to be in good mechanical condition with no technical defects identified, investigators noted that the left-side control stick had become detached from its base. This separation may have been caused by the extreme physical force applied by the occupants during the high-stress recovery attempts.
Analysis of the flight path via GPS confirmed that the aircraft had been performing low-speed maneuvers, likely intended as a demonstration of the aircraft's handling limits. The investigation also noted that the aircraft was not equipped with an emergency ballistic parachute system (BRS) or an installed emergency locator transmitter at the time of the accident.
Findings
- The primary cause of the accident was a collision with the water surface following a loss of control during a low-speed flight phase.
- The aircraft likely entered an asymmetric stall, which, combined with the 15-degree flap setting, induced an unexpected and rapid spin.
- The use of maximum engine power during the spin likely intensified the rotational forces, making recovery impossible.
- The occupants, who did not have specialized aerobatic training, were likely overwhelmed by the rapid onset of the spin and the high-stress situation.
- The two occupants sustained fatal injuries upon impact.