SAAF 01/07/62
Although 35 Squadron was based at the military section of DF Malan International Airport in Cape Town, the unit's headquarters was at nearby Air Force Station (AFS) Ysterplaat and it was at this latter facility that the flight crew of Shackleton 1718 received a full briefing at 12H30 on August 8, 1963. During this briefing, the Operations Officer on duty advised the Shackleton aircrew to head out over False Bay after take-off and to transit seawards towards the exercise area. He warned them that the direct overland route to Port Elizabeth should be avoided due to anticipated high icing levels on this route.
Forecast weather for the route over False Bay and then southwards was poor. Heavy icing conditions could be expected between 1 220 and 1 829 m ( 4,000 and 6,000 ft) above mean sea level (AMSL) and consequently the flight crew were further briefed that Maritime Group had granted them special clearance to transit to the exercise area under 915 m (3,000 ft) AMSL. A 244 m (800 ft) AMSL cloud base would exist with tops up to 6 707 m (22,000 ft). Heavy air turbulence could be expected with cumulonimbus clouds, hail and heavy rain throughout. Surface wind was 42 km/h (26 mph) at 340? and 92 km/h (57 mph) at 340? and 1 524 m (5,000 ft).
Even though the forecast weather over the eastern overland route was no better, at least the seaward route would eliminate the risk of the aircraft accidentally flying into high ground in the conditions of much reduced visibility. The aircraft commander, Captain (Capt) TH Silvertsen , when giving his own briefing, confirmed his route as south over False Bay and then seawards towards the exercise area. The flight had been authorised by Maritime Group to provide the Shackleton crew with training in the radar detection of a submarine. No special instructions were issued.
Shackleton 1718 was fully serviceable for flight even though the compasses had not been swung on their normal expiry date of July 19, 1963. Maritime Group gave authorisation for a month's extension provided that no major part of the aircraft was replaced. The compasses were therefore considered serviceable.
The Flight Office at Ysterplaat was uncomfortable about the weather conditions and telephoned the Maritime Group Operations Centre thrice prior to the departure of the Shackleton, in an effort to get the flight cancelled, but this request was not forthcoming.
Just minutes before take-off, Capt Silvertsen, notwithstanding his briefing instructions, informed Air Traffic Control (ATC) that he would climb to 2 896 m (9,500 ft) AMSL and head overland towards Port Elizabeth.
The aircraft lifted off Runway 34 at 15H06 and turned right on 350? for the climb out. Moments later, ATC informed the commander to come to 330? so as to safely avoid Tiger Mountain. Capt Silvertsen acknowledged this transmission and did accordingly. After the lapse of about a minute, he requested clearance to resume his original course of 350?. This was the last radio transmission received from Shackleton 1718.
At about 15H20 the radar technician at DF Malan requested permission to deactivate the radar for about ten minutes due to flooding of the radar installation on account of the heavy rain. This permission was granted, but before the radar was deactivated, 1718's location was given as a distance on the radar screen of about 40 km (25 miles) on a course of 100?. The ground course was about 145?.
Although the evidence suggested that the airplane had crashed, most likely in the Stettynskloof/Wemmershoek Mountains area, the adverse weather conditions, combined with the lateness of the hour, precluded any meaningful attempt at a search and rescue effort being mounted until the following day, August 9.
At 10H00 and again at 13H30 on August 9, helicopters were sent out to the Wemmershoek area to report on the weather, which remained completely adverse. Following a report of an aircraft having been heard, a further helicopter was despatched at 15H00 to search the mountains south of Simonstown. On August 10, another helicopter continued the search at S