565,207. Aircraft wings. BUDD MANUFACTURING CO., E. G. Feb. 3, 1942, No. 1445. Convention date, March 26, 1941. [Class 4] An aircraft wing comprises a nose-piece 50, upper and lower plates with span-wise reinforcements, cross-ribs 52a, 52b, 52c, and a main spar 58 to the rear of the ribs, all spot-welded together to form a box girder structure with stressed skin, trailing ribs 62 supporting a canvas cover being secured to the rear of the girder. The wing tip 64 is separately formed. The girder structure comprises also a short stub shear web 60 at the root disposed substantially parallel to the main spar 58 and between the latter and the nose-piece, the shear web 60 and spar 58 being adapted for attachment to the aircraft body, a main rib 52c extending over the full chord width of the girder being secured to the outer end of the shear web 60 and to the spar 58 and nose-piece 50. Fig. 4 shows a section of the forward part of the wing at one of the ribs 52a. The nosepiece comprises a metal skin 68 of stainless steel spot-welded to former-ribs 98 and to attachment elements 70, 78 to which the upper and lower skin structures are ultimately secured. Between the former-ribs 98 are reinforcing elements bent to the contour of the nose and formed from two angle-members welded together to form a Z-section. Between the ribs 98 and the reinforcing elements are transversely extending, discontinuous stiffeners 118. The main stressed skin elements comprise plates 210 to which are welded members 212 of the section shown, adjacent flanges embracing flat extensions 216 of tubular stringers 215. Alternatively, members shaped as shown in Fig. 42 may be used. Welded to the string- ers 215 are attachment clips 218. Three different forms of rib are described for use in different positions in the wing, that shown in Figs. 4 and 8 comprising a web plate 128, with vertical corrugations 134 at intervals, welded to members 124 shaped to the required contour. The forward ends of the members 124 are connected to the ribs 98 by gusset plates 104, and the clips 218 of the skin structures overlap the flat sides of the members] 124 to which they are spot-welded. This arrangement obviates the necessity for close tolerances in the construction of the skin structures which are held in their correct positions by jigs while the brackets 218 are welded to the members 124. Figs. 10 and 12 show the ribs 52b for use nearer the wing tip. A web plate 146 with vertical reinforcements 152 is welded to upper and lower shaped plates 142, 144 to which the attachment clips 218 are welded. Members 138, 140, welded to the members 142, 144, extend along the whole length of the rib and forwardly to overlap a plate 114 forming part of a modified nose rib which is reinforced by L-members 110, 116. Where floats or other attachments are secured, the lower skin is braced from the ribs by brackets 149. Figs. 17 and 20 show the rib 52c nearest the root of the wing in which the web consists of a corrugated plate 172 having the crests of the corrugations at one side welded to shaped members 158, 160 and the crests on the other side welded to members 173 welded to the members 158, 160. Channel members 154, 156 extend forwardly over a plate 164 forming part of the nose bracing. The stub shear web 60, extending to the root of the wing, is secured to the rib and skin structures a little to the rear of the nose-piece. The main spar 58 comprises upper and lower members 176, Figs. 24 and 30, welded to corrugated sheets 180, 186, alternate ribs of the sheets 180 being flattened as shown and welded to the members 176. The sheet 186 is backed by a flat plate. The vertical edges of the sheets are welded to L-section members 184 to which are welded the web plates 128, 146 and the plate 162, Fig. 17, of the various ribs. The remaining gaps are filled with channel section members open to the rear and the ribs 62 of the trailing part of the wing are secured within these channel members. The corrugated plates 180 are pierced as shown and the openings strengthened by rings 194, 200. At the root of the wing the reinforcing members 212 of the skin are tapered, and attaching brackets 222, Fig. 32, are welded over them, the sides of the brackets being welded to the laterally flattened parts 228 of the members 216. The bent-up ends of the brackets are pierced to take bolts which secure the wing to the stub wing, strengthening channels being placed inside the end wall of each attaching bracket. The wing tips 64 are separately constructed and comprise upper and lower contour members 262, Fig. 36, outside which are placed stringers 282 supporting the metal plating. The inner edge is closed by a plate 274 and the outside edge by a curved section member 64. Bolts 302 connect extensions of the members 262 to brackets 238 on the end of the main wing. A strip 304 covers the gap. The girder structure is assembled by first securing the nose-piece 50 to the upper reinforced skin which is held in a jig. The ribs are then held in position and the attachment brackets 218 spot-welded to the sides of the rib. The lower reinforced skin is then secured to the ribs and nose-piece, and finally the spar 58 is secured to the ribs and the upper and lower skins. The method of assembly, however, forms the subject-matter of Specification 565,236. The clips 218 and their associated skin structure form the subject-matter of Specification 565,235, and the wing root structure involving the attachment brackets 222 form the subject-matter of Specification 565,234. Specifications 540,652 and 558,419 also are referred to.