New Technique; Moulded Aeroplanes

Manawatu Times, Volume 64, Issue 171, 22 July 1939, Page 8

New Technique; Moulded Aeroplanes

MASS PRODUCTION LIKELY A new technique which promises to revolutionise aircraft construction and make it possible to build aeroplanes in a fraction of the time now required, is being developed in tho United States. Exhaustive tests have proved that a perfectly satisfactory aeroplano fuselage of a new laminated plastic material can be made in a single shell without internal bracing. Before many months, it is expected, wings of the same substance will have been perfected an the mass production of aircraft will be an accomplished fact almost immediately- . ’ .

The technique has been developed in the past five years primarily by a veteran aeroplane designer, Colonel V. E. Clark, who was chief engineer of

aviation to the United States Army during the Great War, and later chief engineer aud vice-president of the Consolidated Aircraft Corporation, Buffalo. With him is collaborating Dr. Leo Hendrik Baekeland, the father of modern plastics. Present Laborious Fabrication

The great drag upon aircraft production, whether for military or civil purposes, is the fabrication of wings and fuselage. All tho component parts, motors, instruments, fittings and structural members, can be turned out with the greatest, speed by modern factory practice, but nothing can hurry tho laborious fittings together by hand of l he elaborate frames aud coverings that make up the orthodox present-day aeroplane. It is estimated that four hours is required to rivet on a single square foot of an aeroplane’s metal skin, and other operations take a correspondingly long time. Colonel Clark has given the name “duramol " to the material from which the successful fuselage has been made according to a secret process employing phenolic resins discovered by Dr. Baekeland: A laminated plastic differs from a true plastic in that it has a base of organic fibre, with resin as an adhesive, forming aud coating

agent. “Duramold" can be moulded inexpensively in a die, without great

heat or pressure, iu shapes at present limited to 40ft iu length. Rapid Production Possible ■ The experimental fuselage, which is said to have withstood every possible test in actual flight for 1600 hours over a period of 18 months, was moulded in two half-shells, glued together longitudinally. Nine men moulded one halfshell in one hour, aud only 5 hours 20 minutes were required to assemble the entire fuselage and fit it, without filing or drilling, to the remainder of the complete aeroplane. This moreover, was an experimental job.

It has been calculated that with 10 sets of dies, 200 semi-sk*iied men iu a factory covering one city block could build enough “duramold" fuselage, wing and tail shells for 300 aeroplanes a month. With 100 dies, 2006 workmen could, in one year, mould aud assemble 36,000 aeroplanes. Very Strong Material The new material is described as resistant to water, oil, and acids, non-chipping, non-warping, an capable of being moulded to within a tolerance of a few thousandths of an inch. In the form jaf a thin-walled cylinder oi given weight under compression, it is stated to be 10.4 times as strong as stainless steel and 3.4 times as strong as aluminium alloy.

In the experimental aeroplane, plywood wings and alloy ailerons and rudder were used. The next stage will be to build a machine with wings of the new plastic. It is not expected that there will be any great difficulty in doing this successfully, as the physical properties of the material are considered to leave an ampie margin of strength. &erodynamically, it is claimed,

“duramould" aircraft will be more efficient than all others hitherto made, owing to the complete absence of rivets, seams, and irregularities of shape, and the theoretical gain in speed is in tho neighbourhood of 7 per cent. It is considered that plastic fuselages aud wings will fare better metal ones under gunfire, because they will have no vital structural points to be shot away. May Aid. Cauac of Peace Commenting on the possible military and political implications of the discovery, the magazine Scientific American remarks: “When the new science of plastics has helped to solve the problem of mass production of aeroplanes, the winged fear that made Munich possible need never be repeated. No one nation will be able to cow another from the air for long. Portugal and Peru, if they wish, may havo fleets at large as those that terrorised Europe last September. ‘ ‘ Prqgondaiaucu in aviation

give way to equality, aeroplanes may become as commonplace and unimport ant in the balance of war aud peace as rifles are to-day. The only possible superiority in the air may depend on morale, flying skill, strategy, and a 4*ady supply of petroleum."