(b)
Unsupported locations 0.20 inch
(c)
Supported and unsupported locations for flammables gas, fuel, and oxygen systems will be 2.0 inches from electrical wires and cables.
S 974-030
(2) Minimum clearance for hydraulic system.
(a)
A minimum 0.06 inch for tubes supported to structure or other rigid members.
(b)
A minimum of 0.25 inch with adjacent structure, tubing or connectors, or other installations.
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(c) (d) (e) A minimum of 0.25 inch in areas where relative motion of adjoining components exists.A minimum of 0.06 inch between individual coils of all coiled tubes.A minimum of 0.05 inch between electrical wiring installations.
(3) S 434-027Install the hydraulic tubes with a minimum force on clamps and/or tubing.
(4) S 224-028At supported locations, make sure the tubes are clear of the adjacent structure by a minimum of 0.10 inch. Where the tubes are attached directly with clamps to the supporting structure, the clearance can be the thickness of the supporting clamps.
(5) S 224-029At not supported locations, make sure all rigid lines are clear of the adjacent structure, equipment installations, and other items by a minimum of 0.25 inch.
(6) S 224-030Make sure the tubes are clear of all operating mechanisms by not less than 0.38 inch. This clearance can be 0.25 inch at supported locations where tubes will not rub or touch the operating mechanism.
(7) S 224-031If tubes go through or across each other or are parallel, make sure there are sufficient clamps attached. Clearance must be 0.25 inch minimum or the thickness caused by back-to-back clamping.
NOTE:____ You can use more back-to-back clamping than that on the supplied airplane to get the necessary clearance.
(8) S 434-032To get the necessary clearances with the loop-type clamps, use BAC S18AF3 or BAC S18AF4 spacers to make the necessary height. On the U-type clamps, use BAC 8SIAN spacers. Do not use NAS42 or NAS43 on hydraulic tubes.
NOTE:____ Do not use more than six spacers together. If you use more than four spacers, find the cause and correct the problem.
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S 224-033
(9) Make sure the tubes are clear of the control cables between the break points or fairleads and the control linkage by a minimum of
0.625 inch.
S 224-034
(10) Make sure the minimum clearance between the tubes in the clampblocks (65B80254) and the channels on the clampblocks is 0.060 inch. If this clearance is less, correct the spacer tube length (NAS43003-) and/or correct the force of the tubes in the clampblock.
TASK 20-11-05-054-026
7. Tubing Clamp Spacing____________________
A. Procedure
S 224-036
(1) Keep the tube clamp spacing in the limits shown in Table 2 unless specified differently.
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20-11-05 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 STANDARD PRACTICES - AIRFRAME(14)
