History of Flight
On 15 December 2018 at 0026 UTC, an MBB-BK 117 D-2 EC145 helicopter (registration G-HEMC) was conducting a Helicopter Emergency Medical Service (HEMS) flight at night in a rural area. The crew consisted of two pilots, and there were no passengers. Visibility was good, exceeding 10 km, with a broken cloudbase at 3,500 ft.
The crew identified a large field for landing. After an airborne check, they made an uneventful approach and hover-taxied to their selected landing site. The medical team on the ground then requested repositioning to a different site in the same field to facilitate patient loading. The team reported wires near a road adjacent to the new site.
One pilot conducted a ground check with a powerful torch and located the reported wires but found no others. The crew also consulted an electronic map showing powerlines (not telegraph lines), which indicated no additional wires.
The helicopter repositioned using its steerable landing light to scan for obstacles. As the pilot attempted to land at the new site, the aircraft felt slightly unstable, prompting a short move before touchdown and engine shutdown.
Aftermath
Upon exiting, the commander discovered a single telegraph wire hooked over the rear radio antenna. Inspection with a torch revealed no damage to the aircraft or the wire; the wire had been pulled from a post in the field that had gone unnoticed during the ground check and taxi.
As a precaution, the patient was transported by road, and the helicopter returned to base for further inspection. Again, no damage or impact marks were found.
Comment
The operator is reviewing technological solutions to aid wire detection and plans to create an overlay map of telegraph wires for their operational area, as such a system is not currently available. The event underscores the difficulty of detecting wires despite thorough reconnaissance from air and ground.