possible to easily exceed this low limitation, especially under conditions of unusually high turbulence as in this case. Although it cannot be proved, it is not impossible that the pilot in control could have over controlled the aircraft on at least one occasion in response to the unusually heavy turbulence. This could have placed an additional load on the airframe.
It was considered a possibility that, due to the turbulence, the pilot found himself unwittingly between the mountain peaks and that either one wingtip or one of the tail surfaces skimmed the side of one of the mountains, the impact causing the aircraft to disintegrate in flight and causing the pilot to lose control. The Board, however, considered this scenario unlikely given the fact that the ATC heard the pilot's Mayday transmission clearly and the aircraft must have thus been flying above the mountain peaks under normal circumstances when the radio call was put out. Additionally, the fact that the dump valves were open does not correspond with a collision against a mountain.
The Board found Capt Silvertsen solely responsible for the accident. He displayed a complete lack of discipline by disobeying a direct order to rather route south over False Bay and instead routed over land, where the mountainous terrain exacerbated the already foul weather conditions. The aerodynamic effect of heavy icing, strong and turbulent winds, the heavy weight of the aircraft combined with the possible over control by the pilot in control, placed an unusually high loading on the airframe. This resulted in the airframe exceeding its design limits and initiated disintegration, leading to the loss of control and the consequent fatal crash. The accident was classed as an avoidable major flying accident.
All the evidence submitted by all the witnesses interviewed was considered credible by the Board.
Shackleton 1718 was delivered new to the SAAF valued at R 417 250.00. At the time of its demise it had completed 775.15 total airframe hours and, with depreciation, was valued with engines and propellers at R 266 109.45. The Rolls-Royce Griffon Mk 57A piston engines, like the airframe, were all classified as having sustained Category IIIa (write-off damage with no salvageable content). Engine numbers were 64411, 64412, 64416 and 64445.
This was the only Shackleton to be written off in 27 years of SAAF service from 1957 to 1984.
The Group Commander remarked that the ultimate load factor was 4 G. This figure suggests that the airframe was considerably stronger than the BOI was made to believe when they made their investigation. This information was, however, not available to the Board at the time.
The only flight crew member of the 13 that perished on board to have received any honours or awards was WO2 (Warrant Officer Class 2) Scully, recipient of the Africa Star with Clasp and the Union Medal (No. 285).
Individual Aircraft History:
1716 / J - c/n1526, first flight 29th March 1957, accepted at the Woodford Airfield by 35 Sqdn on the 16th May 1957, ferried to RAF St Mawgan for SAAF air-crew work-up exercises on the 21st May 1957, Departed for South Africa on the 13th August 1957, arrived Waterkloof on the 18th August 1957, Progressively modified up to Phase III standard. Wing re-sparring took place in South Africa, from March 1973 to April 1976. The aircraft took part in the retirement ceremony flypast at DF Malan airport, Cape Town, on the 23rd November 1984.
She was ferried from Cape Town to the SAAF Museum Swartkops on the 4th December 1984, with Capt Louis van Wyk as aircraft Captain. Restored to airworthy status in 1994, for planned attendance at a series of airshows in the UK. 1716 departed Cape Town International RW01 on the 8th July 1994, for the United Kingdom, routing via Libreville, Gabon, - Abidjan, Ivory Coast, - Lisbon, Portugal for intended entry into the UK via Brize Norton. Crashed 13th July 1994, in the Western Sahara Desert (22.38N, 03.14W) en-route to the UK.
Shackleton 1720 - painted as 1717 - which was on static display in front of the NCO's mess at
Ysterplaat AFB i