What happened
On 31 May 2008, a Robinson R44 Astro helicopter, registration ZS-RKW, was involved in an accident on a public road in Kroonstad. The aircraft was performing a domestic charter flight, transporting three actors for a local television production. After taking off from an open field near a shopping center, the pilot attempted to land again, claiming a passenger had requested to pick up a cameraman.
During the landing approach, the helicopter's tail rotor made contact with the ground. The aircraft subsequently collided with a light delivery vehicle traveling on the road. The impact caused substantial damage to the helicopter's fuselage, rotor blades, and tail boom, while the vehicle also sustained significant damage. One passenger sustained serious injuries, while the pilot and other occupants were largely unharmed.
The investigation
Investigators from the SACAA AIID utilized video footage from a spectator to reconstruct the flight sequence. While the pilot initially reported a hydraulic system failure, post-accident testing confirmed the hydraulic system was fully functional and serviceable.
Analysis of the cockpit controls revealed that the hydraulic switch and the speaker system switch, both located on the cyclic control stick, were identical in appearance and lacked guards. The investigation determined that the pilot intended to activate the speaker system but instead inadvertently toggled the hydraulic switch to the off position. This sudden loss of hydraulic assistance caused the controls to become heavy and stiff, leading to a loss of altitude and a subsequent roll.
Findings
- The pilot accidentally deactivated the hydraulic system while attempting to operate the speaker switch.
- The hydraulic system itself was in a serviceable condition and did not suffer a mechanical failure.
- The pilot's claim regarding the need to pick up an additional passenger was contradicted by passenger statements and the aircraft's seating capacity.
- The flight was conducted as an unauthorized charter without the required Air Service Licence or Air Operating Certificate.
- The aircraft's weight and center of gravity were within safe operating limits at the time of the accident.
Safety action
Following the investigation, it was recommended that the hydraulic switch be fitted with a protective cap to prevent accidental activation. Alternatively, a recommendation was made to the manufacturer to relocate the hydraulic switch from the cyclic stick to the center console to ensure it is not easily disturbed during flight.