Parachutist's Tale of Flying Through Space

Manawatu Times, Volume 61, Issue 11, 14 January 1936, Page 8

Parachutist's Tale of Flying Through Space

“COMING TO EARTH” PROPERLY.

Some interesting facts about tbe parachute were given during an interview with a “Times” reporter yesterday by Mr. G. W. Sellars, who will cooperate with Plying Officer “Scotty” Fraser at Milson aerodrome to-morrow, when a monster flying display will bo held in conjunction with the inauguration of Union Airways air service. Mr. Sellars is a pilot as well as a parachutist and commenced his flying career at North Taieri aerodrome, Dunedin, on Friday, November 13, 1931, when ho took his first flying lesson under Flight-Lieutenant E. G. Olson. “Incidentally this was actually the first time 1 had ever been in an aeroplane and the date which was Friday, the 13th, was not propitious of good luck to one of a superstitious nature. Nevertheless, I am still alive,” said Mr. Sellars. It was in 1931 at Balclutha that he first saw a parachute descent made. This was when “Scotty” Fraser was jumping in that district and it was this experience that imbued him with tho desire to make a jump himself, but it was not till July, 1935, that eventually he made his first descent at Wigram aerodrome in Christchurch.

The parachute, he explained, may be obtained in four standard sizes, 20ft., 24ft., 26ft. and 28ft. to suit different requirements. The size that Mr. Sellars will uso is the 24ft. or service size and made by the Irvin Parachute Company

of Great Britain. It is of the manually operated type which means that the opening of the parachute depends on the jumper and may be opened at will by him after he has fallen clear of the aeroplane. This type has only been in use since late in 1918 when its inventor, Irvin, made the first descent with a manuallyoperated parachute in America. Irvin parachutes arc now standard equipment of the Royal Air Force, as well as for many foreign Governments. The successful opening of the manual parachute depends almost entirely on its correct folding and packing, and although a simple operation is rather a test for a man’s patience and takes approximately an hour. The silken panels of the canopy are first folded in pleats one on top of the other. This forms a narrow cone about 12 feet long which is then folded concertina fashion until it fits the parachute pack.

The next and most exacting operation is the placing of the 24 silken cords suspending from the canopy within the pack. These cords must be packed in such manner as to permit their withdrawal without becoming twisted or entangled when the parachute is opened. The importance in packing these cords may be understood, added Mr. Sellars, when he pointed out that their fouling would probably result in the failure of the parachute to open. The eanopv is next placed on top of the cords,' the pack is partly closed and the pilot parachute is placed within. The pack is then completely closed by the ripcord prongs. The ripcord prongs are short pieces of special steel attached to the ripcord which itself is constructed of lOcwt. steel cable. On the ripcord being tugged the prongs are withdrawn from their cones, the pacK bursts open, and the pilot chute, which is actually a steel spring encompassed by a miniature parachute, jumps out into the slipstream created by the jumper’s falling body and draws the main canopy out in its wake. An ample safety margin is provided and the possibility of any serious structural failure, such as the extensive tearing of the silk or the breaking of suspension lines is very remote. The acceptance test for parachutes requires that a parachute attached to a dummy of -lOOlbs. weight be dropped from an aeroplane flying at 100 m.p.ffi The silk of the canopy is tested to withstand a pressure of 51bs. per square inch, while the actual pressure per square inch in a jump is infinitesimal. The 24 shroud lines each has a tensile strength of at least 4001bs. and the metal harness fittings have a breaking strain of SOOOlbs., or considerable more than a ton each, so it will readily be seen that there is little possibility of trouble through structural failure. The maximum rate of descent for a human body in normal atmosphere is 200 feet per second, but on the parachute opening this is reduced to about 20 or 25 feet per second, and on reaching the ground the jumper strikes it with a force equal to that sustained in jumping from a 10ft. wall. It is Mr. Sellars’ ambition to see the parachute which he described as tha lifebuoy of the air used more extensively in civil aviation and he mentioned the names of recent aviation victims in New Zealand whose lives might have been saved had they worn parachutes. He considered that the parachute gave one a much better chance in jumping from an aeroplane than did a lifebelt in jumping from a ship, and he felt that pilots should be forced to wear them, especially when engaged in test flights or acrobatics and on hazardous cross country flights. The value of a parachute (about £9O) was little compared to the amount involved in training a pilot, to say nothing of the value of a human life.