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51-00-00
ALL ú ú 01 Page 4 ú Jun 10/88
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL
C. Section 48, the fifth fuselage section, is not pressurized. It extends aft from the rear pressure bulkhead at station 2360. The vertical fin structure and the horizontal stabilizer structure are supported by Section 48. The auxiliary power unit (APU) is installed in a fireproof compartment in this section.
3. Wings
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A. The primary wing structure consists basically of the left main wing box, the wing center section, and the right main wing box. The left and right main wing boxes are cantilevered from the wing center section which is enclosed within the fuselage. The thickness and chord of each wing taper from inboard to outboard and, in plan view, both wings sweep back from the wing center section.
B. The left and right wing boxes consist of upper and lower skin panels stiffened by spanwise stringers, front, mid, and rear spars, and chordwise rib structure. The front and rear spars enclose the forward and aft portions of the box and consist of vertically stiffened webs attached to upper and lower chords. Chordwise ribs enclose the reamining portions of the box and consist of rib chords and web stiffener construction. The wings are also supported by the wing landing gear beam acting as a spar through the fuselage to reinforce the wing landing gear and wings. The wing boxes are sealed to serve as fuel tanks. The wing center section is reinforced by spanwise beams.
C. The leading edge structure on each wing is cantilevered forward from the front spar. The trailing edge structure is cantilevered aft from the rear spar and supported additionally by the wing landing gear beam and the trailing edge beam. These structures make up the wing control surfaces and include leading edge Krueger flaps, variable camber flaps, trailing edge triple-slotted flaps, spoilers, and ailerons. The variable camber flaps provide a large curved leading edge and slot for takeoff and landing.
4. Winglet
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A. The winglet is a removable airfoil attached to the outboard end of the left and right wing and is made of nomex honeycomb and epoxy impregnated graphite fabric spars and ribs. The spars and ribs are enclosed by a nomex honeycomb and epoxy impregnated graphite fabric skins. The winglet is faired into the wing by rigid fairings which are attached to the winglet and the wing.
5. Wing-to-Fuselage Attachment (Fig. 4)
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A. The outboard wing boxes are joined as one unit to the wing center section in the fuselage.
B. The wing and fuselage are connected by body fittings bolted to the front, mid, and rear spars, the scalloped upper side of body ribchords, and the keel beam tie to the lower wing surface.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
51-00-00
ALL ú ú 01 Page 5 ú Jun 10/88
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL
BODY STRUCTURE (FUSELAGE)
SPLICE PLATES
WING CENTER SECTION REAR SPAR TERMINAL FITTING WING
LOWER SIDE
WING-TO-BODY
RIB
MID OUTBOARD
FWD SPAR WING
BODY UPPER SIDE
FITTING WING FRONT WING-TO-BODY RIB
TERMINAL SPAR
FITTING
Wing-to-Fuselage Attachment
Figure 4
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：747-400 AMM 飞机维护手册 结构 STRUCTURES(3)
