The Construction of Aircraft in Steel: Some Reasons for Preferring this Material, with the Results of Ten Years' Research and Experience

THE material used for the construction of the wings of nearly all the aircraft made up to ten years ago was wood, generally silver spruce. Steel tube was sometimes used for the fuselage and tubular steel spars had occasionally been used in the wing structure. While wood un‐doubtedly gave excellent service, it was felt that something more durable and more uniform in its properties was required. Sir W. G. Armstrong Whitworth Aircraft, Ltd., of which I am chief engineer, began experiments in metal construction in 1917. The first aeroplane made by this firm in which the whole of the structure was of steel was flown in 1918, and production in series began in 1923. Since then very large numbers of aircraft have been constructed chiefly for the British Royal Air Force, both by my own firm and by four other British constructors, who have made similar aircraft under licence. The purpose of this paper is to give some of the reasons which led to the choice of steel, to describe the system of construction used, and to tell of the experience gained in the manufacture and supply of steel aircraft during the last ten years.