What happened
On 5 May 2008, a Schweizer 269C helicopter, registration G-WARK, was conducting a private flight from Bagby. As the pilot approached a private landing ground located approximately 3 nautical miles east of Sherburn-in-Elmet, the aircraft encountered an object in the rotor path. During the process of reducing engine speed and preparing to shut down the engine, the main rotor struck an empty, woven fabric cement bag. The bag, which was capable of holding roughly one tonne of material, was blowing in the wind near the landing site. The impact caused the rotor blade to fly out of its proper track.
Despite the imbalance caused by the strike, the pilot successfully landed the Schweizer 269C at the landing site located at his residence. There were no injuries to the pilot or the single passenger on board, though the aircraft suffered extensive damage to the airframe, including the tail boom and the cabin.
The investigation
Investigators examined the circumstances surrounding the debris at the landing site. It was established that building work was being conducted at the pilot's premises at the time of the incident. The investigation determined that the empty cement bag was likely associated with this ongoing construction work. The physical properties of the bag, specifically its woven fabric construction, meant that even when empty, it represented a substantial object in terms of bulk when caught in the airflow.
Findings
- The primary cause of the incident was the impact of a large, empty cement bag with the main rotor blade.
- The bag was a woven fabric type with a capacity of approximately one cubic metre.
- The debris was present at the landing site due to ongoing building works at the pilot's home.
- The resulting imbalance caused the rotor blade to deviate from its normal track, leading to extensive damage to the cabin and tail boom.