What happened
On 5 August 2007, a Robinson R44 Raven II, registration ZS-OSP, was engaged in commercial aerial photography for a television production covering the Eston Illovo mountain bike race in KwaZulu-Natal. The flight crew, consisting of a pilot and a cameraman, had been flying throughout the morning to capture various stages of the event.
During the final stages of the mission, the pilot was maneuvering the aircraft to follow a leading cyclist. To ensure the cameraman could capture the best possible footage, the pilot was focused on the right side of the aircraft. While tracking the contestant, the pilot noticed high-tension wires approximately five meters ahead. In an immediate attempt to avoid a collision, the pilot flared the helicopter and lowered the collective pitch to fly beneath the cables. During this maneuver, the main rotor blades struck the first of three parallel 11 kilovolt power lines, severing it. The pilot successfully navigated under the remaining two wires and performed a safe landing in an open area between sugar cane fields. There were no injuries to the occupants.
The investigation
SACAA AIID examined the circumstances surrounding the wire strike, including the aircraft's maintenance history and the pilot's operational focus. The investigation confirmed that the Robinson R44 Raven II was properly maintained, with its last periodic inspection completed earlier that year. The pilot held a valid commercial license and the operator possessed a valid Air Operating Certificate.
Investigators determined that the power lines were positioned approximately 9.9 meters (32 feet) above the ground. The analysis revealed that the pilot's attention had been diverted from the primary responsibility of obstacle avoidance due to the secondary objective of positioning the aircraft for optimal filming. While the pilot's evasive action prevented a direct impact with the wires, the maneuver itself led to the rotor blades contacting the first conductor.
Findings
- The pilot's attention was diverted by the requirements of the filming task, specifically the need to maintain position alongside a cyclist.
- The pilot failed to maintain an adequate lookout for power lines while operating at a low altitude.
- The aircraft's main rotor blades struck and severed one of the three parallel conductors.
- The terrain, consisting of uneven agricultural land, made maintaining a constant height difficult.
- The incident occurred during daylight with good visibility, and the aircraft was within its weight and balance limits.