What happened
On March 25, 2021, a Guimlam G2 Cabri helicopter, registration OK-GUI, was performing a series of recreational maneuvers at Kladno Airport. The pilot, who was conducting a private flight with one passenger, had been performing low-altitude maneuvers between runway markings on Runway 30. The pilot intended to conclude the sequence with a left-hand braking turn into the wind, aiming to come to a stop in visual conditions.
During this maneuver, the helicopter's left skid struck rising terrain near the threshold of Runway 12. The impact caused the aircraft to pitch forward and to the left, leading to the main rotor blades striking the ground. The helicopter subsequently overturned and came to rest on its left side. The pilot successfully evacuated the passenger, who had sustained serious injuries to her leg, and summoned emergency medical services. The aircraft was destroyed due to the impact and rotor contact with the ground.
The investigation
The ÚZPLN investigation examined the aircraft's condition, the pilot's qualifications, and the meteorological environment. Technical inspections of the wreckage revealed that the tail boom had broken, the landing gear was deformed, and the main rotor blades were significantly damaged. However, no evidence of mechanical failure or engine malfunction was found; the engine had ceased operation due to the force of the impact. The investigation also noted that the aircraft was within its permitted weight and center of gravity limits.
Regarding the pilot, the investigation established that while the pilot held a valid CPL(H) and type rating, they had very limited experience on this specific model, with only approximately 13 hours of total flight time on the Guimbal G2 Cabri.
Findings
- The primary cause of the accident was uncontrolled flight during a low-altitude braking turn.
- The pilot's corrective actions—attempting to increase collective pitch and level the aircraft with cyclic control—were either performed too late, were insufficient, or a combination of both.
- Contributing factors included the pilot's limited experience on the aircraft type and the execution of the maneuver toward rising terrain.
- Variable wind conditions at the time of the accident increased the difficulty of the low-altitude maneuvering.