What happened
On June 2, 2017, a Robinson R44 Raven II helicopter was performing a landing at the Hohe Düne special landing site (HSLP-YHD) in Warnemünde, Germany. The pilot had previously coordinated the arrival via telephone with the harbor master, who had advised that the aircraft could not remain overnight on the designated landing spot and would need to be moved to a northern open area.
As the helicopter approached the landing site from the north at a low altitude and reduced forward speed, the harbor master, wearing a high-visibility yellow vest, walked toward the aircraft from the pier. At approximately 17:15 local time, the main rotor of the helicopter struck a 6-meter-tall light pole located at the eastern edge of the pier. The impact caused the tail boom to buckle and the tail rotor assembly to break away from the fuselage. The helicopter subsequently crashed to the ground on its side, coming to rest with the engine still running.
The three occupants of the aircraft were able to exit the wreckage independently. The pilot sustained abrasions, and the harbor master suffered a laceration caused by flying debris. The aircraft was heavily damaged, and the collision destroyed the light pole.
The investigation
The BFU investigation reconstructed the flight path using GPS data from a Garmin aera 795 unit on board, as well as witness statements and surveillance camera footage. The investigation examined the aircraft's maintenance history, the site conditions, and the operational procedures at the landing site. Investigators also noted that while the pilot was familiar with the location, the cranes on the pier had not been moved away from the landing area as required by local regulations.
Findings
- The primary cause of the accident was the main rotor striking a light pole during the landing phase.
- The impact resulted in the immediate structural failure of the tail boom and the separation of the tail rotor.
- At the time of the accident, the cranes on the pier were not positioned away from the landing area, which was a violation of the established safety procedures for the site.
- The harbor master was walking toward the approaching aircraft, a maneuver that deviates from standard practice where pilots typically land with a view of the signalman and avoid flying over them.