Aeroplane Construction and Operation

by John B. Rathbun

Fig. 31. Typical Fuselage Strut Fittings.

An old form of fuselage connection used on the Nieuport monoplane is shown by Fig. 33, an example of a type in which the bolts are passed through the longeron member. This fitting is very light but objectionable because of the piercing of the longeron.

An Austrian aeroplane, the Hansa-Brandenberg, has a wood fuselage in which no stay wires are used. This fuselage is shown by Fig. 23a. Both the vertical and inclined members are wood struts. The outer covering of wood veneer makes the use of stay wires unnecessary since the sheath takes up all horizontal stresses, and hence forms a sort of plate girder construction. The German Albatros also employs a wireless veneer fuselage, the construction being shown in detail by Figs. 36 and 36a. Three longerons are located on either side of the body, the third member being placed at about the center of the vertical side. As will be seen, the veneer makes the use of wire bracing and metal connections unnecessary. The veneer also insures perfect alignment.

Fig. 32. Fuselage Strut Fittings of the Standard H-3 Training Biplane.

Wing Connections. The lower wings are attached to the lower longitudinals by a special sheet steel fitting which also generally connects to a vertical strut at this point, and to an extra heavy horizontal strut. A sheet metal clevis, or socket, on the wing spar is pinned to the fuselage half of the fitting so that the wing can be easily detached when the machine is to be dissembled. At this point a connection is also provided for the end of the inner interplane stay wires. The horizontal strut at the point of wing attachment is really a continuation of the wing spar and takes up the thrust due to the inclination of the interplane stays. In the majority of cases the horizontal thrust strut is a steel tube, with the hinged connection brazed to its outer ends. This is one of the most important and heavily loaded connections on the machine and should be designed accordingly.

Fig. 33. Fuselage Fittings of the Nieuport Monoplane.

Fig. 37 shows a typical wing to fuselage connection of the hinge type. The wing spar (G) is covered with a sheet steel ferrule (A) at its inner end. Two eye bars (B) are bolted to the wing spar, and over the ferrule, the eyes of the bar projecting beyond the end of the spar. This forms the wing half of the connecting hinge. The eyes are fastened to the fuselage hinge member (H) by means of the pin (E). This pin has a tapered end for easy entry into the joint, and is pierced with holes at the outer end for cotter pins or a similar retaining device. The fuselage hinge member (H) is brazed to the end of the steel tube strut (T). This tube runs across the fuselage from wing spar end to wing spar end.

Strut tube (T) lies on, and is fastened to, the fuselage longeron (L), and also lies between the two halves of the vertical strut (S). The vertical strut is cut out at its lower end for the receipt of the steel tube (T). A steel plate is brazed to the tube, is wrapped about the longeron (L) and is bolted to the vertical strut (S). The interplane stay (F) is attached to the pin (E) at the point of juncture of the wing spar eye and the fuselage member of the hinge. A collar (I) is brazed to the tube, and forms a means of attaching the fuselage stays (D). The drift wires (C) of the wings are attached to an eye at the end of one of the wing spar bolts. As shown, the fitting (H) is a steel forging, very carefully machined and reduced in weight. The inside wing ribs are indicated by (K), from which it will be seen that there is a gap between the end of the wings and the outside face of the fuselage.

Fig. 36. Veneer Fuselage Construction of the German "Albatros" Speed Scout. Body Outline Is Obtained by Veneer Diaphragms and no Stay Wires Are Used.

Fig. 36-a shows the construction of the wing joint of the German Albatros machine. The fuselage is of monocoque construction which allows of a simple attachment to the outer shell. This is a very sturdy and simple connection. Fig. 38-Z is the wing attachment detail of the English London and Provincial Biplane (1916), the fuselage in this case being of the wire trussed wood type. We are indebted to "Flight" for this illustration.