What happened
On the morning of 10 February 1999, a Mi-8 MTV-1 helicopter, registered ZS-RIP, was engaged in a specialized cargo delivery mission in Cape Town. The objective was to transport a cooling system to the roof of the Foschini Building. Due to high winds the previous day, the operation had been rescheduled for first light on the 10th.
The flight originated from the Newlands Forest Heli-port. After departing, the aircraft proceeded to the Grand Parade to hover and attach two sections of the cargo to a sling. Once the load was secured, the helicopter flew west along Strand Street, which had been closed to traffic for the maneuver. As the aircraft approached the Boston House building, the pilot executed a 90-degree right turn to position the load. After a second 90-degree right turn, the helicopter hovered facing east, positioned near an advertising board on an adjacent structure.
During this hovering phase, the tail rotor made contact with the "Stannic" advertising board. This contact triggered an uncontrolled anti-clockwise spiral. The tail boom swung approximately 180 degrees, striking a building wall and severing the boom from the fuselage. The aircraft then plummeted nose-first onto the roof of Boston House, where it burst into flames and experienced subsequent minor explosions. There were four fatalities among the crew and passengers on board; no other injuries were reported.
The investigation
Investigators examined the flight path, the mechanical state of the ZS-RIP, and the sequence of maneuvers performed during the final positioning phase. The inquiry focused on the proximity of the aircraft's tail rotor to the nearby advertising board and the subsequent structural failure of the tail boom upon impact with the building wall.