On 6 July 2021, around 09:30 hrs LMT1 a pilot of the Robinson R44 (Raven I) helicopter, SP-CCC registration marks, took off from a private property in Mikołajki to perform a recreational flight to the EPUL airfield in Ułęż. The pilot was a male, holder of PPL(H) and there were two passengers on-board.
The temperature in the helicopter cabin was very high. Shortly after take-off, during acceleration and altitude gain, the pilot wanted to pull the cabin air knob, but by mistake he pulled the mixture control knob, which leaned the mixture and, as a result, the engine shutdown. The pilot immediately realized what had happened and pushed the knob back immediately, but it was too late.
The main rotor RPM began to drop sharply. Light and sound signals alerted the pilot of that fact. The pilot moved the collective downward to switch to auto-rotation flight. During the descent, the helicopter was controllable. Due to the low speed and height (about 40 m AGL), it was not possible to return to the operational RPM of the main rotor.
Just above the water surface, the pilot increased the collective angle of attack of the main rotor blades by raising the collective. Due to too low RPM of the main rotor, he did not manage to fully stop the descent and the helicopter ditched hard in the Tałty lake in Mikołajki.
As a result of the collision with water, the pilot lost consciousness, which he regained after choking on water, and then instinctively surfaced. At that time, one of the passengers has already surfaced, and the other one joined her after a while. A private motor boat approached them and they were all taken on-board.
A few minutes later, PSP and Police boats arrived and the survivors received first aid.
The pilot and passengers were seriously injured and were taken to hospitals. The helicopter was destroyed and its wreckage came to rest at a depth of over a dozen meters under water. In the afternoon the helicopter was recovered and secured for PKBWL investigation.
During the Investigation PKBWL determined the following cause of the accident: Pilot error, resulting in the engine shutdown after take-off.
1) High ambient temperature as well as inside the cabin.
2) Pilot’s habits acquired on different helicopter model.
3) Time pressure caused by limited availability of airspace.
4) Lack of conditions to perform full autorotation (low helicopter height and speed)
PKBWL has not proposed any safety recommendation after completion of the investigation.
Read the report.