Robinson R44 Raven II Wire Strike Incident at Eston, KwaZulu-Natal (ZS-OSP)

Incident Overview and Flight History On 5 August 2007, a Robinson R44 Raven II helicopter, registration ZS-OSP, was involved in an incident in the Eston area of KwaZulu-Natal, South Africa. The aircraft was operated by National Airways Corporation for a Durban-based client to conduct aerial television filming of the annual Eston Illovo mountain-bike race. The pilot-in-command, a 46-year-old South African with a valid commercial pilot's licence and 6,038.1 total flight hours, was accompanied by a television cameraman. The flight departed Virginia Aerodrome at 0425Z and proceeded to the Eston Club, the race's starting point. After several takeoffs and landings to film various stages of the race, the crew refuelled at a nearby farm. At approximately 0850Z, they took off again to film the final stages of the race. ## Sequence of Events While following a leading female contestant on the final section of the course, the pilot was looking to the right to maintain position alongside the cyclist for optimal camera footage. The pilot then noticed high-tension wires directly in front of the helicopter, approximately 5 metres away. In an attempt to avoid a collision, the pilot flared the helicopter and lowered the collective pitch lever. The main rotor blades struck and severed the first of three parallel 11-kilovolt power lines. The pilot successfully flew the helicopter underneath the remaining two wires and executed an uneventful landing in an open area between sugar cane fields. ## Damage and Injuries No persons were injured in the incident. The pilot and passenger were secured by safety harnesses. Damage to the helicopter was limited to the main rotor blades, which showed visible evidence of the wire strike. The severed power line was repaired by Eskom approximately three hours later. ## Investigation and Probable Cause The investigation determined that the probable cause was the pilot's evasive action to avoid colliding with power lines, during which the main rotor blades struck and severed the first conductor. The pilot had a valid aviation medical certificate, and the aircraft was maintained under a valid Air Operating Certificate. The last mandatory periodic inspection was certified on 20 April 2007 at 204.2 airframe hours, with 93.9 hours flown since that inspection.