What happened
On 14 May 20 and 21, a Robinson R44 Raven II helicopter, registration ZS-RSK, crashed into the water at Vaal Marina Bay, Gauteng. The aircraft was operating under private Part 91 regulations, transporting a pilot, a passenger, and two dogs from Rand Airport to a landing strip near Burgundy Bay.
While the flight began in daylight under visual meteorological conditions, the approach to the landing site occurred under night conditions. To assist the landing, the pilot had requested that a spotlight on a nearby house be activated. Video footage captured by an eyewitness showed the helicopter approaching the landing site over calm, mirror-like water. During the maneuver, the aircraft descended rapidly and struck the water surface. The impact caused the main rotor to sever the tail boom, leading to the separation of the tail rotor assembly and gearbox. The helicopter subsequently overturned and sank.
The crash resulted in two fatalities, involving both the pilot and the passenger. One dog was recovered from the wreckage, while the second dog was recovered several days later. The aircraft sustained substantial damage and was eventually recovered from a depth of 9.13 meters.
The investigation
The investigation utilized video evidence from a witness on the ground to reconstruct the final moments of the flight. The footage showed no mechanical anomalies or engine issues during the initial approach. Investigators examined the environmental conditions, noting that the water in the bay was exceptionally calm and "glassy."
Findings
Investigators concluded that the primary factor in the accident was the glassy water illusion. The mirror-like surface of the water likely caused the pilot to misjudge the aircraft's altitude, leading to a false perception of being higher than the actual height. This resulted in a sudden reduction in altitude that brought the helicopter into contact with the water surface.
Safety action
Following the incident, a safety recommendation was issued suggesting that the Director of Civil Aviation mandate the installation of emergency floatation devices on helicopters that operate over large bodies of water, specifically those involving take-offs or landings over water. Additionally, a safety message was issued advising helicopter owners operating near large water masses to consider installing such devices.