Are these the first pictures of the doomed Rietbok plane?

To some the images may seem unremarkable — splodges of grey against a yellow background. To plane-wreck hunter Wouter Botes, the underwater pictures of the ocean bed off East London are almost certainly the missing pieces of a 57-year-old mystery.

The high-res 3D images, captured last month, appear to show the wheel and undercarriage of the SAS Rietbok, a commercial passenger aircraft that disappeared — presumed crashed into the sea — on a flight from Port Elizabeth to Johannesburg via East London on a stormy night in 1967. Botes says the images have lifted the veil on the Rietbok’s ocean gravesite, a breakthrough made possible by new marine electronics — and a personal quest to uncover the truth about one of South Africa’s most enduring mysteries.

Five crew and 20 passengers died in the accident, among them a well-known US anti-apartheid activist, Audrey Rosenthal, and several prominent South African businessmen. Two years ago Botes isolated the probable wreck site based on sonar images, but armed with the latest images he says he is now ready to start diving on-site. “Certain of the [wreckage] targets were confirmed — now we are selecting which targets are the most likely and valuable,” Botes told the Sunday Times this week in response to queries. “There is one very clear image of what could only be an aircraft wheel.”

Another shape — which the digital software identifies as metallic — corresponds to the length of the missing aircraft’s undercarriage. 

In addition to achieving better resolution, recent technological advances enable accurate analysis of the images, allowing Botes to distinguish between the natural ocean environment and probable man-made objects such as wreckage.

The inaccessible disaster site — it  is 65m deep and a fair distance off the coast  in an area known for swift currents — has proved fertile ground for suspicions of foul play related to the crash, which happened during the apartheid years. Rosenthal was reportedly under surveillance in South Africa prior to the crash, and she had visited Port Elizabeth (now Gqeberha) as the guest of a progressive member of the Broederbond who had criticised the apartheid government’s racist policies.

However Botes believes the combined evidence gathered to date, and the wreckage on the ocean bed, will confirm human error was to blame for the tragedy and that the pilot was flying too low to avoid storm clouds.

“When he turned left [on the approach to East London], his wing touched the water,” said Botes, himself a pilot, who has reconstructed the plane’s likely trajectory based on a study of altitude and voice recording data. “He was a wonderful pilot, very experienced, but complacent.”

The plane had made a similar manoeuvre earlier in the day when approaching Port Elizabeth airport, according to a man who had been on the aircraft. “He [the passenger, who disembarked in Port Elizabeth] was also a pilot and said he had got a fright when he saw how low the plane came in under the clouds.”

At the time of the accident there were witness accounts of the events, including a farmer who claimed to have seen the plane crash into the sea from his property above Kayser’s Beach.

Colleen Fletcher, a long-time Kayser’s Beach resident, for years collected unusual pieces of metal flotsam, which she sent to the East London Museum for analysis, suspecting they may be linked to the crash.

“I didn’t know what they were but I used to joke that I’m going to be able to build my own aeroplane one day. The pieces were very hard, not like a tin can. Eventually it was confirmed that yes, the pieces were from the Rietbok.

“I still find pieces now and again — I found one just the other day,” Fletcher said.

The South African Heritage Resources Agency said this week it was collaborating with Botes. “It would also be the only known aircraft wreck to have been found in South African waters, which makes it archaeologically unique,” said SAHRA maritime archaeologist Briege Williams.

“Therefore, while the aircraft falls outside of SAHRA’s mandate, the agency has been available to Mr Botes in an advisory capacity, and he continues to keep the maritime unit updated of his progress. When the remains are eventually old enough to fall under the National Heritage Resources Act, SAHRA may look to place a more formal protection around the site.”

The East London Museum is also co-operating with Botes. Kevin Cole, principal natural scientist at the museum, said: “Our collaboration will become essential if bits of the wreck are salvaged, as material ... will be evaluated for its display and educational value before any narrative is attached to the same. Important would be to interpret the facts surrounding the event and to appropriately display what took place, acknowledging that respect be given to surviving family members of the victims who died.”

If major sections of wreckage were recovered, “it will lay the foundation for further research and will reveal the great challenges involved in dealing with material that lies at a depth of approximately 65m on the seabed”,  he said.

John Minnie, technical manager for local marine electronics supplier Lowrance South Africa, said the company had provided Botes with a state-of-the-art scanning device that gave a clearer view of the ocean bed. Usually associated with finding fish, the technology had previously been used to help police locate submerged bodies. “This is the first time ... to see if we can find a plane — it is something completely different and very interesting for us to be a part of,” Minnie said.

Botes, who has researched other aviation mysteries and also produces film content, says a final salvage mission is largely weather dependent: “We have no guarantee of salvage, due to the sea conditions.”