Tuesday 23 May 2017

CHAPTER 8 THE PARACHUTE HOW IT WORKS AND OTHER TRIALS


After UDI, but before things began to heat up, we had little to do, and as the saying goes, the devil makes work for idle hands. This definitely applied to the PJIs. Someone found a photograph of a French parachute taken from directly underneath the inflated canopy. It said this parachute would go up with 80kgs if towed behind a vehicle at 10kms per hr. We studied the photograph carefully then took one of our parachutes normally used for ground training and duplicated all the numerous holes as shown.

The next trick was to borrow a Land Rover from the MT section, get hold of a volunteer and a long rope, and try it out. As it was he who had discovered the photo, Bill Maitland, the School Warrant Officer claimed first go. We asked Salisbury Tower for use of the 32 Runway to carry out an experiment with a parachute that went up instead of down. They were intrigued and so was every airman at New Sarum. Soon the 32 Runway was lined with spectators keen to check out what the loonies at PTS were up to now.

 Bill got into the harness; Trevor Smith got into the Land Rover and inched forward to take up all the slack in the rope; the rest of us held up the canopy and on the word from our leader, Boet Swart, Trevor gunned it.  Bill started to run. His steps got bigger. And bigger. And Bigger. He looked like an uncoordinated ostrich. And like the ostrich, he did not go up one inch. It was like watching a cartoon, hilarious, but a complete failure.

It was not until a few years later we discovered the parachute used in the photograph, was the French version of the Para Commander which is now used at various venues around the world to drag tourists into the air behind a speed boat. What the photograph we had did not show was that the apex of the canopy had been pulled down and moved forward. This then formed an aerodynamic shape which created lift. We only found this out when we obtained some Parra Commander parachutes at a later stage, by which time we were far too busy to play around.

But even at this time it was not all fun and games. We were, in fact, trialling, modifying, and eventually choosing parachutes to suit our conditions. After the breakup of the Federation we needed to build the SAS to full strength, and did a fair number of parachute jumps during recruiting drives. Everything continued as before. We’d been taught by the RAF, were equipped with British equipment, and, as far as training was concerned, nothing was going to change. We were expected to just behave ourselves, and keep doing it the way it had always been done. Don’t rock the boat was the rumbling from the Air Staff. But, being silly colonialists, and devil may care PJI’s the first thing we did was start playing with the gear the British had given us.

At first we were supplied with the British X type parachute which was developed during WWII, and had not been modified at all. It had a flat canopy made of a nylon fabric (not silk) which, when laid out flat, measured 28ft (8.5mt) in diameter. Each of the 28 gores was divided into 5 panels with a vent in the middle of the circle measuring 22inches (55cm) in diameter.

There were 14 rigging lines attaching the harness to the canopy, but as each line went completely over the top of the canopy, there were 28 lines in all, each with a breaking strain of 500lbs(200kg). The harness was made of 4 thicknesses of flax webbing, each with a breaking strain of 3000lbs(1350kg). All the seams were stitched 2 or 4 times, and were extremely strong.  It’s safe to say the harness was almost unbreakable. All the metal fittings, such as the quick release box, adjusting buckles, and ‘D’ rings for the reserve parachute, and suspended loads, had breaking strains in excess of 5000lbs(2300kg). In other words, it was very bloody strong.

The main problem with the X type parachute was its tendency to oscillate which could cause high speed encounters with the ground. The reason for this oscillation was the build-up of pressure inside the canopy which tended to tilt it, allowing some of the air to escape. The parachutist would swing under this tilting canopy until gravity overcame the force of the escaping air. This pendulum effect was dangerous, especially if contact with the ground was made on the downward swing.

So, an experiment was done to an X type parachute which had been damaged and was going to be written off. We made the damage worse. We cut out two gores, five gores apart, then positioned these holes at the rear when the canopy was fully deployed. We also added two pieces of rigging line stitched to the outer edge of the holes with a piece of wood at the bottom end to form a toggle. This was fitted to the front lift webs with a small piece of tape sewn to form a loop through which the rigging line passed just below the rigging line attachments We figured by pulling on a toggle it would distort the hole in the canopy and make it  rotate in that direction
  

This photograph shows a 28ft dia X type parachute canopy with a seven gore T.U. modification. The sleeve in which the canopy is packed with the pilot chute can be seen as  a shadow on the outside of the canopy. A seven Gore T.U. was the maximum modification we ever tried and even this was stretching our luck a little. The maximum we ever used on HALO operations with a 35ft dia SAVIAC, was a double blank 5 gore separation which worked well especially on dark nights.





All we had to do was convince the safety equipment workers that this would work, persuade them to do the modifications and pack the thing so we could try it out on a dummy. The Safety Equipment Section nearly had a fit. It was sacrilege. It was idiocy. Cut up a parachute and still expect it to work? Ridiculous. But we prevailed. The dummy drop worked and I jumped it the next day.

It was an absolute joy. By pulling down on a toggle the parachute turned in that direction and, in still air, it moved forward at about 5 mph (8kmph). But best of all it was absolutely stable with no oscillation. In fact, because it was such a stable parachute, it had a slower rate of descent, about 19 feet per second as against 22feet per second for a full canopy. Serious thought was given to modifying all of our X types but we were told we’d be re-equipped with modern parachutes in the near future and to stop modifications before we did something really silly.

In 1964, after the breakup of the Federation, the staff at PTS were given a number of different static line military parachutes to trial. One, called the PX, was of British design it was basically a 32ft copy of the 28ft, ordinary X type. It still had a tendency to oscillate and the rate of descent was much the same - we decided we preferred the old X type. It would have been improved if a couple of gores had been removed as per our modification.

The PX also had a skirt made of some type of netting fitted around the periphery of the canopy. This was supposed to reduce chances of blown periphery malfunctions caused by the higher dropping speed of more modern aircraft. This was not a problem for us as we still had the good-old Dakotas. Beside this, the PX was still fitted with the antiquated harness which still needed to be adapted to the individual, the canopy could not be jettisoned, and there was still no way to strap a weapon to the soldier for ready access on landing.



This is a very rare photograph of a 28ft dia X type parachute with a blown periphery malfunction which has reduced the drag area of the canopy dramatically. This SAS paratrooper has pulled his reserve parachute rip cord, carried out the correct drills and is about to land with his feet tight together. This jump took place in about 1966 on our training DZ runway 32 Salisbury Airport and the soldier concerned was Sgt Jock Hutton ex British Parachute Regiment and ‘D’ Day veteran.

In February 1967 we obtained a few French parachutes called the TAP 665.We got them via sources in Mozambique for trial purposes. This parachute also had little to offer over the X type. It did not have a significantly slower rate of descent and its manufacture and harness design had no improvements.

In April 1967 we received a very strange static line parachute. It was basically made up of three parachute canopies sewn together to form a triangle. It was obtained from an Eastern Block source, and was possibly of Russian design. We were willing to give most things a go but in this instance decided to draw the line at jumping this contraption. I don’t know what became of this piece of parachuting history, it just disappeared.

In July 1967 the Parachute Training School finally got hold of a number of PT 10 American parachutes. These were a huge improvement on all the static line military parachutes we’d tried up to this time. Its shaped canopy eliminated the oscillations and its increased size (35ft in diameter) slowed the rate of descent from
22ft per sec to about 16ft per sec. In addition this parachute was fitted with the Capewell canopy release system enabling the parachutist to jettison his canopy after landing. Other improvements included a body band on the harness which allowed the parachutist to carry his weapon strapped to his side instead of on 15ft of rope. This, as far as the staff at PTS was concerned, was the greatest improvement to military parachuting since the 1940s as the soldier had his weapon at hand immediately on landing.

There was another improvement to the PT10 parachute which we gleaned from a film which showed American paratroops in training.  In this, we noticed the troops hooked their static lines to the overhead cable in the Dakota as opposed to the British method of side cable and strop. Of course we had to try it out, first with a dummy, which worked, and then with the PJIs, which was again successful. We were able to greatly improve the aircraft drill with this method. There was absolutely no doubt in our minds the PT10 was the parachute for us.

The only drawback was the fragile nature of the Rip Stop nylon used in the canopy construction of the PT10. It was far easier to damage during tree landings. In the American context this parachute would have been discarded on operational jumps, but we did not have this wasteful option. Still, this was the parachute we were determined to have.

Due to sanctions we could not purchase the original, but eventually obtained a South African made copy called the SAVIAC. We ordered them from a company called P.I.S.A.( Parachute Industries South Africa) which was a  part of the Republic Of South Africa Government Arms Corp. Luckily for us, the SAVIAC  canopy was made of a much more robust nylon material and was not easily torn when tree landings occurred. We also had a number of these parachutes modified to TU status and they worked well in the HALO (High Altitude Low Opening) context at a later stage.





The above photograph shows a Royal Australian Air Force D.H.C.4 Caribou, an aircraft which was an absolute pleasure to parachute from and may have enabled the PJI's of the Rhodesian Air Force to do many more silly experiments.


The occasional aircraft was also trialled. In June 1964 we had the pleasure of jumping out of a Caribou aircraft ,which, in our opinion, would have been a great addition to our parachuting aircraft. It had excellent short take off and landing capability (S.T.O.L.) and a rear ramp which enabled us to parachute big items. However this pipe dream was not going to happen and we had to make the most of our Dakotas.

Although we never really stopped experimenting or looking for new and better ways to do things, once the SAVIAC was chosen and supply organised we were ready for the next step in the saga of the Parachute Training School.

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