5.
Nose Gear Drag Brace
A. The nose gear drag brace, in conjunction with the nose gear lock link assembly, holds the nose gear in the up or down, locked position (Fig. 3). The drag brace consists of an upper and lower link. A projecting lug which is integral to the upper drag brace link is the attach point for the door operator mechanism. The upper end of the upper link pivots on pins through support fittings attached to the wheel well sidewalls. During gear retraction, the upper link rotates upward and aft. The lower end of the lower link pivots about a pin, which attaches it to double lugs on the outer cylinder. These lugs are located just above the steering collar. During gear retraction, the lower link also rotates upward and aft relative to its pivot point. The upper and lower links are bolted together forming a hinge.
B. A fitting located near the lower end of the upper drag link, containing a spherical bearing, is the attachment point for the nose gear actuator. During gear retraction the upper drag link is forced to rotate upward and aft by the nose gear actuator. This motion is transmitted to the shock strut through the lower drag link to raise the gear to the up position.
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32-21-0 Page 8 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. Aug 15/68
509 Nose Gear Drag Brace
Aug 15/68 Figure 3 32-21-0
Page 9
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
NOSE LANDING GEAR - REMOVAL/INSTALLATION
1. Equipment and Materials
A. Shock Strut Restrainer - 6ME65-73762, or F70263-1
B. Ground Lock Assemblies (Ref 32-00-01)
C. Nose Gear Sling - F80182-1 or polyester web slings 12 feet long, 3 inches wide, 2000 pound minimum rated capacity, eye and eye configuration. CWEE1-63, 12 feet long. Cambridge Wire Cloth Co., Cambridge, Maryland (Fig. 402). Use to transport nose gear.
D. Spanner Wrench - AN8514-7 or F72959-4
E. Trunnion Pin and Bearing Puller Set -F80158-1
F. Grease - MIL-G-21164 or MIL-G-23827 optional to BMS 3-33 (Ref 20-30-21)
G. Naphtha - P-D-680 solvent (Ref 20-30-31)
H. Corrosion Preventive Compound - MIL-C-11796, Class 3 (Ref 20-30-21)
2. Prepare for Removal
A. Depressurize hydraulic system A (Ref Chapter 29).
B. Install ground lock assemblies (Ref 32-00-01).
C. Remove nose gear wheel well doors (Ref 32-22-11, Removal/Installation).
D. Remove aft access panel from left nose wheel well bulkhead to gain access to nose wheel steering (NWSA, NWSB) and nose gear piston position cable (NGPPA, NGPPB) turnbuckles and left trunnion pin jamnut (12) (view 1).
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Sep 01/02 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 32-21-0 Page 401
E. Loosen steering and piston position cables at their respective turnbuckles outside the wheel well left bulkhead.
F. Disconnect nose wheel steering cables (view 2).
(1)
Remove lockwire (30) from spring pins (32) at NWSA and NWSB cable terminal ends which lie in a groove in the steering collar (33) (view 2).
(2)
Remove spring pins (32).
(3)
Remove NWSA and NWSB cable terminals from groove in steering collar.
G. Disconnect nose gear piston position cables (NGPPA, NGPPB) (view 4).
(1)
Remove cotter pins at ends of cable terminals (38) on each side of the piston position cable quadrant (37).
NOTE: Terminal (38) is shown removed from its groove in quadrant (37) as cable turnbuckles have been loosened. Removal is typical on each side of quadrant.
(2)
Remove cable pulley bolts (35, 36), remove pulleys and detach cable ends from quadrant.
H. Remove lockwire from cap screw (22) on inboard left trunnion pin nut lock (21). Remove cap screw and nut lock (view 1).
I. Remove left trunnion pin nut (19) using face spanner lug wrench adapter (view 1.)
J. Pull pressure seal (24) and ring (25) inboard from inboard end of left trunnion pin (view 1).
NOTE: The eye of the eyebolt (26) which holds pressure seal segments together may be used to pull seal from trunnion pin.
K. Remove eyebolt (26) to remove pressure seal retainers (27, 28) from pressure seal segments and separate segments from around piston position and steering cables (view 1).
L. Pull cables through left trunnion pin and coil outside wheel well left bulkhead.
(1)
Remove NWSA, NWSB, NGPPA and NGPPB cable guards outside of wheel well left bulkhead, so cables can be pulled through pulley bracket.
(2)
Pull cables through nut (19), ring (25), trunnion pin (20) and coil cables outside of wheel well left bulkhead.
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