What happened
On March 13, 1967, a Vickers Viscount, registration ZS-CVA, was performing flight SA 406 as part of a scheduled service from Port Elizabeth to Johannesburg, with planned stops in East London and Bloemfontein. As the aircraft approached its destination, the crew monitored deteriorating weather conditions near East London. While the captain had initially considered bypassing the airport due to the visibility, the final radio transmission occurred at approximately 1709 GMT, noting the coastline was visible while at an altitude of 2,000 feet.
Shortly after this communication, at 1710:08 GMT, the aircraft impacted the sea at a location near 33°13.45’ S., 27°38.3’ E. The flight was carrying 20 passengers and 5 crew members, totaling 25 fatalities. Following the impact, search and rescue efforts were initiated by naval units. While some debris from the cabin interior was found floating or washed onto the shore, the primary wreckage settled at a depth of roughly 180 to 220 feet. Subsequent attempts to recover the main structure were complicated by heavy currents and low visibility.
Findings
Official investigations into the crash were unable to establish a definitive cause. Investigators ruled out several potential factors, including engine failure, structural disintegration, fire, or mechanical malfunctions. The inquiry also dismissed pilot error and weather-related accidents as primary causes. However, investigators could not rule out the possibility that the captain suffered a sudden medical emergency, such as a heart attack, which led to a loss of control that the first officer was unable to rectify before the aircraft struck the water.