What happened
On 22 June 2007, a Robinson R4CO Raven II, registration ZS-RVZ, was conducting a commercial demonstration flight at Greystones Heliport in Durban. The flight was intended to demonstrate a mock vehicle recovery process to an insurance company employee and clients located in another nearby helicopter.
The pilot began the operation by hover-taxying the aircraft from a refueling bay toward the helipad to establish a suitable takeoff path. During the takeoff run, while the aircraft was climbing at an indicated airspeed of 40 kts, the main rotor blades collided with an antenna pole attached to the corner of the Altech Netstar building. This pole extended approximately 1.5 m above the roofline. Following the impact, the pilot lost control of the aircraft, which descended and struck a steel boundary perimeter and a security wire fence.
The collision caused significant damage to the Robinson R44 Raven II, including damage to the cockpit, canopy, and tail rotor. Debris from the rotor blades was propelled into the parking area, striking and damaging two parked vehicles. While there were no fatalities, the air tracker on board sustained serious injuries, and the pilot suffered minor facial injuries.
The investigation
SACAA AIID examined the sequence of events and the environmental conditions at the time of the accident. The investigation established that the aircraft was well within its maximum takeoff weight and that the pilot held a valid commercial license. The investigation also noted that the aircraft had been properly maintained, though there was a delay in the payment of the Certificate of Airworthiness currency fee.
Investigators looked into the positioning of aircraft at the heliport, noting that other helicopters were parked near the pad. This presence necessitated that the pilot move the aircraft further back from the refueling bay to find a clear path, altering the intended takeoff trajectory. Additionally, the investigation reviewed the meteorological conditions, noting a 15-knot westerly wind was present during the maneuver.
Findings
- The primary cause of the accident was the main rotor blades striking an antenna pole on a building structure, which led to the loss of control.
- A 15-knot westerly crosswind contributed to the aircraft drifting toward the building during the takeoff run.
- The presence of other helicopters at the helipad restricted the available takeoff path, forcing the pilot to hover-taxi to a different position to attempt a clear run.
- There were no established procedures for the operator regarding start-up and hover-taxi maneuvers from the refueling area to the helipad.