|
There was also additional information that will help to explain the accident. I was a second-year student at the Military Academy at the time and was in charge of the squad of second-years that were seat-ushers for the VIPs around the dias. We also practised every day and I give my observations of the day. A lot of speculation as to the cause of the accident was discussed in the Air Force and the BOI members had a diffucult task as there were no such things as DFDRs, CVRs, GPWSs etc. in those days There were three days of practise flypast runs prior to the event on 31 May and not to spoil the event by flying four times over the Dias, the practise runs had to break away to the right as they approached the R101 Voortrekker Rd. Normally the prevailing wind is the southeaster, so the the wind was from the front and helped to push the formations into the turn after the break-away. With a southeaster, the prevailing weather in Cape Town is blue skies.
Upon breaking away at the same place with the same amount of bank (rate of turn) like in the previous practises, where there was a head-wind and no overcast, Table Mountain was plainly in sight and it was safely avoided. On the day of the accident however, a little coastal low had slipped down the west coast and there was a northerly breeze (following wind) with low overcast at around 2000' AGL with Table Mountain obscured, but the run-in path OK as I recall, so the third and now a much more controlled practise flypast went ahead.
In the early 70s there was no on-board equipment that displayed groundspeed or good heavens, the wind, so timing on a run-in was controlled by using power inputs to change the airspeed, using the stopwatch to compare features on the map/ground to ascertain the groundspeed, ie being early or late at a specific point and then repeating this process continually until you reach the dias. With a tailwind on the day of the accident, the groundspeeds were a lot higher with the same power-setting as under south-easterly conditions and it could well have been that all formations ended up a little early further back in the run-in as the previous two days. Power adjustments were made and it is very easy to fall behind if you were a few second early, reduced power and 30 seconds later you were still early, reduced power even more and at the next point 30 seconds or so on, you suddenly find the formation now being a few seconds late, but with the dias/break-away now looming close-by and a lot of formations behind you. Nobody wants to be late, so a good handful of power is added under these situations. It was therefore highly probable that the Mercurius formation could have been a bit late quite far down the run-in path, had a lot of power on and reached the break-away point a little bit hot and cranked on the bank of the previous practise runs. With with the concomittant higher air- and groundspeed, the turning circle would have been a lot wider plus the north-wester was pushing them further out of the turn, ie a lot more to the south and the path over the grond now not clearing the mountain as before. Maybe this situation was picked up a bit late, as the previous turns were OK and Table Mountain plainly visible Now the mountain was obscured by the cloud and the formation in trouble far into the turn. One could only speculate as to the consternation and panic in the cockpits. If I remember correctly, no 2, who was looking left and up to his leader, impacted virtually in his position in the formation and No3 looking down and to the right towards his leader and maybe having had Table Mountain in the left corner of his eye, started pulling up causing him to impact slightly higher-up than the other two.
Truly a sad day
|
Login
Register
FAQ
Search
