Investigation Summary
The flight's day was marked by several minor incidents, including a nosewheel retraction failure on an earlier leg from Johannesburg and a bird strike during the flight to Port Elizabeth. The aircraft was inspected upon landing at Port Elizabeth, where it was determined to be airworthy for the multi-leg return journey to Johannesburg via East London and Bloemfontein. Due to deteriorating weather at East London, including low clouds and drizzle, Captain Lipawsky took on extra fuel to allow for a possible diversion to Bloemfontein. During the descent, the pilot reported being at 2,000 feet and having the coast in sight at 17:09 GMT. Approximately one minute later, the aircraft impacted the sea at high speed. The investigation was severely hampered by the depth of the water (180 to 220 feet), strong currents reaching 8 knots, and murky conditions, which prevented the recovery of the flight recorders or the main structure. While the official report remained inconclusive, later analysis by investigators like Judge Cecil Margo suggested structural failure of a wing spar, citing similar contemporary Viscount accidents. In 2022, independent researchers claimed to have located the wreckage and proposed that a failure to recalibrate the altimeter for low local air pressure led to a 'black hole' effect, causing the pilot to fly lower than intended until a wing clipped the water during a turn.
Final Conclusions
The official Board of Inquiry concluded that the available data was insufficient to determine the originating cause of the accident with any degree of probability. The Board explicitly excluded structural failure, control failure, engine failure, and fire based on the limited evidence available at the time, though these exclusions were later questioned by individual board members. The report noted that a heart attack suffered by the captain could not be excluded as a potential cause for the loss of control.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
Gordon Benjamin Lipawsky
First Officer
Brian Albert Richard Trenwith
Systems & Failure Modes
Altimeter
Pressure-sensitive instrument used to determine altitude; researchers later theorized it was not correctly calibrated for the low local air pressure.
Wing Spar
The main structural member of the wing; later theories suggested a spar failure caused in-flight disintegration, similar to other Viscount accidents of the era.
Interesting Facts
- 01The aircraft was named 'Rietbok' and was one of the Vickers Viscounts purchased from the Cuban airline Cubana.
- 02The wreckage was located at a depth of approximately 68 meters (223 feet) in 2022 by a private research team.
- 03Two high-profile critics of the Apartheid government, Johannes Bruwer and Audrey Rosenthal, were among the passengers.
- 04The official investigation lasted four months and was conducted by the South African Board of Inquiry.
- 05The approximate position of the crash was 33°13.45’ S, 27°38.3’ E.
Safety Actions & Advisories
Vickers Viscount Wing Spar Inspections
Source ↗Following several Viscount accidents involving in-flight disintegration, including MacRobertson Miller Airlines Flight 1750, global airworthiness authorities mandated increased inspection frequencies and eventual replacement of wing spar lower boom components to address fatigue cracking.
Pilot Health Screening
Source ↗Although the Board could not definitively prove pilot incapacitation, the inquiry highlighted the risks of sudden medical events, reinforcing the importance of rigorous cardiovascular screening for commercial pilots.
Known Controversies & Unanswered Questions
Apartheid-era Sabotage Allegations
Reference ↗Due to the presence of two anti-apartheid activists on board and the government's initial failure to recover the wreck, rumors persisted for decades that the aircraft was sabotaged by the security branch.
Disputed Structural Integrity
Reference ↗Judge Cecil Margo, a member of the original inquiry, later publicly disagreed with the official findings, stating he believed the crash was caused by a wing spar failure similar to other Vickers Viscount losses.