BUILDING OF AEROPLANES.

Press, Volume LXVII, Issue 20158, 10 February 1931, Page 14

BUILDING OF AEROPLANES.

A FLOURISHING INDUSTRY. REVIEW OF 1930. (MOlt Olfft OWN (*ORIIESP(JKtIE»T.> LONDON, January 2. In a year of slumps and financial troubles tho youthful industry of a via* tiun lias steadily progressed. Civil Hying lias continued to advance at tho phenomenal rate first reached throo years ago. In tho three countries where aviation is! malting most progress —the United States, Canada, and Australia—the graphs of P ro * gress continue to climb steGply. Though the market for military aircraft lias shown small cxpah* sion in numbers of machines employed, yet technical advances in the design of aeroplanes and aero engines have ensured orders for new material. In 1929 Great Britain headed the aircraft export trade of the world; the figures so far available fO) - 19<i0 j. 1" cate that she should retain that '"S™ position. Further, big orders received from overseas during the last few weelts promise foreign trade in 1931 equal to 1 lie best yet achieved. Long and painstaking research ou aircraft desigil problems and intensive aero engine development has resultod iu the production of British fighting aeroplanes, winch are admittedly superior in speed, rate of climb, ease of control, and general efficiency to those produced in any other country. For example, latest types ol ! single-seater fighters constructed in Great Britain attain speeds with tun military load on board which are only reached by stripped racing aircraft bunt abroad. Similarly, new British day and night bombers, service flying boats, and seagoing war aeroplanes definitely surpass all foreign competitors. The year has seen tho building in Great Britain, and first successful flights of tho world's largest passcngercarrying land aeroplanes, the emergence of the largest float seaplane yet constructed, and the production of othei big mail and passenger-carrying craft and freighters which, while capable o£ improved performance, are actually cheaper to build and simpler to tain than their less efficient P redec ®®" sors. Early in 1931 many of these new big craft will bo place.! in commission on air lines in many different partfl of the world. The result-is certain to be a reduction in operational costs and a gain in safety and regularity which will improve markedly tho economics, of civil aviation. New Engines. In addition to the design and lmilding of engines which are definitely su perior in efficiency and power de T® l " oped to earler types tlie British aelo engine builder has continued the sturty of new means of power production. An example of novelty in engine design is the 16-cylinder 300 h.p. air-cooled motor, shown in public for the nr.t time at the Royal Air Force display, devised to overcome the greatest disadvantage of the generally employed air-cooled radial motor—large frontal area and resultant big resistance to movement through the air. The new nower-plant has four banks of cylinders, arranged like the uprights of a capital letter "H," and presents a verv small "resistance area. Ino efficiency of this _ arrangement was proved when a single-seater fighter, specially built around the engine, attained a speed of 110 less than 203 miles an hour at a height of 20,000 feet. Tn several laboratories the work of building a practical compression-igni-tion engine, burning heavy oil instead of petrol, goes steadily on. Considerable success has been achieved, and tho era of aircraft powered with oil-burn-irig motors, promising more economical, simpler, and safer flying* is appreciably nearer. , . A multitude of accessory devices luivo contributed to the increased efficiency of tlie aircraft of 1930. To mention one, the Towneild ring device lia« done much, to overcome the resistance disadvantage of the star-radial engine. Aeroplanes equipped t with this simple mechanism, which consists of a v.idc, flat ring placed around the motor at its greatest diameter, gain astonishingly iti speed and range. An increase of ten miles an hour frequently follows adoptioh of the ring. Economy also is gained because aircraft equipped with rings will cruise at the same air speed as When "unringed," for a lesser opening or the .fuel throttles. Metal Construction. The tendency towards metal construction has almost, reached the logics 1 , conclusion and' woo 4 is rarely found in the main structure of aircraft produced in any quantity in Croat Britain to-day. Inventors nave discovered how to build wings ana fuselages, in metal which are lighter, stronger, and easier to fepftir than wooden' structures. During tlie year certain aircraft liaVe been built in Great Britain of mefc&l, even to the coverings of the wings an<l hull. Business Man's Aeroplane. Mote than six thousand miles in ton weeks is the record of the Westland Wessex inonop>lan(j air-liner, iwh'ich completed recentlv a demonstration tour of the British Isles. The aircraft visited 22 aerodromes, serving 60 of the larger cities and t:iwns in Great Britain and tho Irish Free State, and made no fewer than 250 landings and ascents. Considerably more than a thousand leading business men and municipal officers were present at demonstration flights and many of them went aloft for tho first time in tho machine. Weather conditions -were poor over most of the tour and sometimes extremely bad, With low cloud, mist, and rain squalls. The Irish Sea was crossed twice and on the return journey the craft flew the 143 miles over tho water in eighty minutes. The Wessex is a passenger aeroplane of moderate size with comfortable space for six occupants, and was designed primarily for feeder or branch lines connecting up with main air routes, air taxi flying, or private use as an air yacht. It is. powered with three aircooled motors of around 120 horsepower each and cruises at 95 miles an hour. Craft of this kind are giving satisfactory service on routes operated by Imperial Airways an. by Sabena, tho Belgian air transport company. A New Air-Fighter. Typical of modern British practice in constructing high speed military aircraft around a radial air-cooled engine is the Gloster 5.5.18, a single-seater interceptor fighter designed primarily to operate in the air defence of London. The machine is therefore designed to climb very rapidly to a great height and to maintain high speed even in the rarefied air found four and five miles above the earth. The 5.5.18 is built entirely of metal and embodies a number of features making for efficiency and accuracy of fire in aerial combat. Powered with the Jaguar MajOr motor of 525 horse power, the fighter has an estimated top speed of no less than 207 miles an hour, and is able to remain aloft for 3J hours at a height of 20,000 ft, while cruising at 150 m.p.lu A Worthy Society. A new stage in the progress of the oldest body in world aeronautical science, the Royal Aeronautical Society, i«

marked by the issue of an appeal fot subscriptions to atf" endowment fund with whieh to provide a site and erefct a building where the society may find a permanent home. Not less thin £50,000 is needed. . * The Royal Aeronautical Society was founded in 1868 and has continued without a break since tli<f foundation day an intensive study of the varied scientific and technical problems associated with the grbwth of aviation. , The result is a collection published papers on every aspect of flying. The long list of past and present members of the society is an epitome of flving history. Btringfellow, ■ Glaisher, WcSiiham among the "aneients"; Handley Page, Fairey, A. V; Roe, Siddelcy, Sopwith among the moderns, are names taken at random. Distinguished foreign experts bulk large among those who have read papers before the society. Scarcely an important man in foreign aviation> indeed, has not at some time addressed the members. The importance Of the Work done by the' Society is recognised , in annual grants from leading trade organisations, while for five years the Daniel Guggenheim fund for the promotion of aeronautics contributed annually £IOOO. A permanent home cannot fail to enhance the great prestige of the society and to increase Hb •usefulness in the developing science of aeronautics. Compression Ignition. Within the last few - days details llavo been revealed of work done w> Air Ministry instructions in the conversion of certain types of Rolls-Royce aero engines to "compression-ignition working. Experts at the Royal Airoraffc establishment, Farnborough, have designed special cpmponent parts for a "Condor" 650 horse-power unit, and, in its new guise, the engine has maintained steady and economical output of power. A second engine, in form a cOhverted "F" type unit (developing in its normal petrol-burning shape about 500 hotse-power) is being fitted with special parts for oil-burn-ing, and will begin test running early this year. Power units of this type possess great advantages in aircraft operation, apart from the vastly diminished risk of fire. They consume less weight of fuel than a . petrol engine. and are far less complicated. Further, the successful engine of this type is certain to be more dnrable and to require less attention than even the best petrol-consuming units. The explosive mixture in the cylinders is fired simply by high compression without the intervention of sparking plugs connected to a magneto or accumulator. Fuel economy in any kind of internal combustion engine depends to a large extent on the pressure at which the mixture is fired and the "compression-ignition'' unit is accordingly less voracious of fuel than a petrol motor. The result is'that, although the oil engine is inevitably heavier than the petrol-consuming engine, it is much more economical on long flights. It is generally estimated that, ■ employing ''compression-ig-nition" motors of weights which could be attained in the present state of knowledge, an aeroplane would become more economical than a petrol-burning craft of equivalent horse-power after the first ten hours of flight. In this Way the effective range of aircraft may be considerably increased without adding _ to the laden weight of the machine at: the moment of e^oent..