What happened
On 9 November 2006, a Robinson R44 Raven II helicopter, registered ZK-HUC, was performing a low-level coastal search for the police near Motukutuku Point, Westland. The aircraft was carrying the pilot and three police officers. During the operation, the helicopter struck electricity transmission lines, causing the windscreens to shatter and a piece of copper wire to penetrate the pilot's chest.
Following the impact, the pilot managed to land the aircraft on a nearby beach. Although the helicopter sustained minor damage, the pilot suffered a serious injury. After landing, the pilot moved the aircraft to a different location to assist with recovery, a decision later identified as problematic due to his physical condition and the potential for further damage.
The investigation
Investigators examined the flight path, the visibility of the wires, and the pilot's preparation. The investigation established that the flight was a lawful commercial transport operation conducted at an appropriate speed and height. However, the investigation looked into why the wires were not detected before the collision. It was noted that the transmission lines and their supporting poles were difficult to see because they blended into the surrounding vegetation. Furthermore, the specific lines involved were not marked on aeronautical or topographic charts, and the exact location data held by the network provider was not publicly available for pre-flight planning.
Findings
- The electricity lines were invisible to the pilot because they blended with the natural landscape.
- The pilot did not become suspicious when the lines disappeared from view, as he believed they might have been routed underground.
- The pilot had not conducted a reconnaissance flight prior to descending to low level, which might have revealed the hazard.
- The pilot had not specifically briefed the passengers on the potential hazards of low-level flight or their role in spotting obstacles.
- The pilot's decision to move the aircraft after the accident was influenced by his injuries and lacked necessary engineering consultation.
Safety action
Following the incident, the operator updated its Operations Manual to require a reconnaissance flight of at least one mile prior to low-level operations and to include hazard briefings in pre-flight procedures. Additionally, efforts were made by electricity network associations to make infrastructure data more accessible to pilots to improve situational awareness.