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Aviation History
1974
1974 - 0293.PDF
FLIGHT International, 28 February 1974 Private ighl Hot-air balloon record flight As reported in our February 7 issue, Julian Nott and Felix Pole rose to 44,550ft in the hot air balloon Daffodil II over central India on January 25. Assuming it is officially ratified, this altitude easily beats the previous record of 35,971ft also set by Julian Nott. The balloon is the largest of its type yet made, with a volume of 375,000 cu ft. putting it in the largest AX10 class. The canopy made by Cameron Balloons of Bristol used 31,000 sq ft of nylon material and weighed over 5001b. It is a scaled-up version of the AX8 class balloon of 140,000 cu ft, in which Don Cameron flew over the Alps in 1972. The pressurised tub-shaped gondola is GBP, reinforced with carbon fibre, with flat honeycomb panels top and bottom. The pressure was released slowly through a relief valve as the balloon rose, to maintain a fixed pres sure differential. The pilots wore partial-pressure suits and breathed oxygen for two hours before each flight lo wash out nitrogen from their bloodstreams to avoid the "bends", the painful release of nitrogen bubbles in the muscles during the ascent. Parachutes were also worn. The first flight from Bhopal was a trial run with Julian Nott and Boger Munk, the gondola designer, on board; severe turbulence was encountered at 30,000ft and with the burner off, the balloon descended at over 2000ft/min to 18,000ft. The burners were relit at 15,000ft and a landing was made in a 15 m.p.h. wind. When the balloon was unpacked for the next flight, there was some con sternation when one of the load tapes was found to be broken. Eventually it was found that the damage was not due to the turbulence, but to a mis chievous onlooker helping himself to a souvenir. The second flight was a test run, following repairs, to a mere 20,000ft, then, on January 25, the record flight was made. After a straightforward climb, tur bulence was again found at around 40,000ft, and the burner was turned down to reduce the rate of ascent. At 42,000ft, with the turbulence increas ing, it was turned off, and the balloon climbed to an indicated 44,500ft. 263 Since the turbulence had eased, relight was attempted, but failed, the low temperature preventing vaporisa tion of the propane. In fact, liquid propane (boiling point —40°C) dripped down onto the gondola, making relight too risky, so the climb was abandoned. The burner relit normally at 10,000ft to slow the descent for touchdown, and a landing was made 100 miles downwind of the launch point. The method of emptying the balloon on touch-down was ingenious: the flying wires were released by a lever- operated system, and the canopy, re strained only by a line to the crown, inverted itself, spilling out the heated air. On this occasion, a fouled lift wire prevented a clean release and the gondola rose again before it could be freed and the landing finally made. Transatlantic balloon attempt A completely new strategy was being employed by US Army reserve colonel Thomas Gatch, aged 48. in his attempt to cross the Atlantic by balloon last week. All the other attempts relied on classic ballooning techniques, inevitably consuming gas and ballast with the winds available at these moderate altitudes. The journey would take longer than the period for which reliable forecasts could be expected and the balloon would almost certainly enter low- pressure centres or convection areas, which were highly unfavourable to ballooning. Colin Mudie started westwards in his Small World G-APOB in December 1958, ditched after some 1.200 miles and completed the crossing in his boat like gondola. The hot-air balloon piloted by Malcolm Brighton set oil eastwards across the. north Atlantic in September 1970 and, after reporting position some 1,200 miles out, disap peared with all three occupants. Last August. Bob Sparks in Yankee Zephyr set out along the same route and was safely picked up off Newfoundland after some 800 miles. Col Gatch chose to fly high in the jetstreams using a cluster of ten transparent plastic super - pressure balloons of 26ft diameter. During ascent, the balloons would expand without venting until they reached a stable density and then would main tain height. Gatch himself was to travel in a sealed gondola maintaining 0-5 atmos pheres pressure with a 40 per cent concentration of oxygen, giving the same oxygen partial pressure as at sea level. He set off from Pennsylvania on February 18 and, according to fore cast, was to be carried by jetstreams over to Spain in something like 52 hours. The speed of the crossing made a good forecast possible and Gatch carried good radio equipment, but he was soon plotted to be passing south of Bermuda at 140 m.p.h. on Tuesday. There was a slight setback during initial ascent after take-off, when one Above, proportion is given to ••Daffodil II" by the normal sporting balloon alongside. Below, the gondola during launching of the ten balloons burst and Gatch had to vent water ballast to re-estab lish the climb. Though he could safely survive the loss of two balloons, he was now committed to "cruise" at some 36,000ft instead of 39,000ft. Airliners kept a look-out for him and at least two were re-routed before his craft, the Light Heart, left the air ways to the south. He was later sighted by a merchant ship oil I he Canaries at an estimated 1,000ft. Eight of his ten balloons were still inflated. It is thought that Ihe liqhl Heart. which is well equipped and will float, is down in the Atlantic or the Spanish Sahara, and a search is being carried out.
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