History of Flight
The pilot, accompanied by a Netstar Air Tracker in the left front seat and an insurance company employee in the right rear seat, planned to demonstrate a mock vehicle recovery to clients in another helicopter near the helipad. The demonstration was to occur over the Nandi petroport, about 2 km south of Greystones Heliport. Another helicopter was parked on the eastern side of the helipad.
The pilot started the engine and hover-taxied from the refuelling bay to the helipad area to initiate a take-off run in a north-easterly direction, left of the Altech Netstar building. During take-off at 40 kts indicated airspeed, the helicopter climbed normally until the main rotor blades contacted an antenna pole attached to the left corner of the Altech Netstar building. The antenna protruded approximately 1.5 m above the roof. After the strike, the helicopter lost height and crashed into the steel boundary perimeter and security wire fence near the entrance gate.
Injuries and Damage
The pilot sustained slight facial injuries. The air tracker sustained serious injuries and was hospitalised. The insurance company employee was not injured.
The helicopter was substantially damaged: main rotor blades damaged, left-hand skid broken off, cockpit, canopy, and tail rotor damaged on impact with the boundary fence. Two parked vehicles were also damaged by flying debris from the main rotor blades. A piece of a main rotor blade leading edge sliced through the left-hand pillar and window of a sports utility vehicle (SUV) parked in the designated parking zone, then continued to damage another vehicle parked at the side of the building. The antenna pole broke off on impact.
Other Details
The helicopter was a Robinson R44 Raven II (registration ZS-RVZ), operated by National Airways Corporation CC. The pilot held a commercial licence with 285.8 total flying hours, 70 of which were on type. The helicopter's take-off weight was 2 166 lbs, well below the maximum 2 500 lbs, with no CG exceedance indicated. Weather was fine with westerly wind at 15 kts, creating a left crosswind. The pilot broadcast intentions on VHF 120.6 MHz prior to take-off. Greystones Heliport is a licensed heliport.
Probable Cause
During take-off, the main rotor blades struck an antenna pole on top of a building roof structure, resulting in the pilot losing control of the helicopter, which crashed. Contributory factors included restricted take-off area due to parked helicopters requiring a longer hover-taxi, and a westerly crosswind of 15 kts.