FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1928
1928 - 0108.PDF
FEBRUARY 16, 1928 THE SUPERMARINE S.5 : On the left, a three-quarter rear view of the fuselage, showing wind screen andcylinder block fairings. On the right, a view inside the engine cradle. way, the efficiencies of machines of widely differing power (the S.5 of about 875 h.p. and the " Tiger Moth " of about 130 h.p.) Concerning the features of design which enabled this low drag to be attained, Mr. Mitchell gave in his lecture previously referred to the main changes as between the S.4 and the S.5, and the gain in speed which he attributed to the various changes. As these figures were given in FLIGHT of February 2, 1928, it is not proposed to repeat them here. The photo- graphs published on p. 95 will serve to show how small are the frontal areas of fuselage and floats in the S.5, and these and other illustrations give an idea of the care taken in streamlining unavoidable projections, and in fairing the various surfaces into the fuselage The brief specification at the end of these notes contains the main available data relating to the machine and it is of interest to note that the " Wing Power " is the highest of any machine ever described in FLIGHT, being no less than 7-6 h.p./sq. ft. (81 -7 h.p./sq. m.). Constructional Features Although in a pure speed machine like the S.5 the aero- dynamic design is perhaps the more interesting, there are a number of constructional features which are somewhat unusual, and which were developed as a result of the special conditions to be met with in a high-speed machine. The fuselage of the S.5 is built entirely of metal, chiefly Duralumin, and an examination of the photograph of the fuselage in skeleton will show that by using this material and making the body more or less a monocoque, a good deal of space was saved so that it became possible to keep the cross-section down to a minimum. In fact, the pilot sits on the floor, and as his shoulders touch the metal skin of the fuselage the only space lost is represented by the thickness of the Duralumin skin ! The method of building up the fuselage is fairly clear from the photograph. Closely-spaced frames or formers of flat U-section give the form of the fuselage from point to point, while the skin is made to serve in the capacity of longerons, i.e., is a part of the stress- resisting structure, reinforced here and there by fore-and-aft stringers. In the forward portion there are specially strong frames for the support of wing roots, undercarriage struts and, at the top, for the attachment of the anti-lift wire bracing. The reason why the latter point is one of great importance in the design is that with the system of bracing used, this point serves to stabilise the bracing of the whole machine, floats as well as wings. The location of this " key point " may be seen in the photographs, and details of the fittings etc., are shown in a sketch. The front bottom portion of the fuselage is built up as an engine bearer, with two main bearers of box section secured to cradles. In this region, as well as between the spar frames, the Duralumin plating is laminated so as to give extra strength, a maximum of three thicknesses of 18 G. being required in places. With the scoop-formed engine Photograph of one wing of the S.5. Note the diagonal member which stiffens the wing tip against torsion. 96
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
