R B. Protection of the Wing Leading Edge (Ref. Fig. 006)
When a pneumatic or anti-icing duct leak occurs, the pressure in the wing fixed leading edge bay(s) of the wing(s) increases. This continues until the rivets which attach the two angles of the landing shear. Then the trailing edge of the access panel moves and the air flows overboard.
The pressure at which the rivets shear depend on:
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the shape and the size of the access panel,
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the number of rivets which hold the panel,
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the rivet shear strength.
To shear the rivets, a pressure of approximately 0.48 bar (7 psi) is necessary. The adjacent skin structure is made to hold pressure of 1.03 bar (15 psi).
If, after the access panel has 'blow down', a close inspection shows no damage, the panel and the landing can be used again. To install the access panel replace the attachment angle of the leading edge and the shear rivets.
R C. Protection of the Pylons (Ref. Fig. 002, 003) When a pneumatic duct in any area of the pylon breaks open or leaks, the pressure increases in this area. It continues up to a differential pressure of 0.20 bar (2.90 psi). This causes:
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the pressure to overcome the force of the spring on the doors 413BL and 432BL.
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the rivets to shear on the doors 471BL and 482BR.
The doors open and stay open to allow the overpressure to flow overboard.
R D. Protection of the Nacelles (Ref. Fig. 004)
When a pneumatic duct breaks open or has a large leak, the pressure in the nacelle zone increases. At a maximum differential overpressure of
2.90 psi (0.20 bar) the door opens automatically and the overpressure decreases.
INDICATING - DESCRIPTION AND OPERATION
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1.
General
_______ The indicating system shows the condition of the pneumatic system. It monitors the bleed air pressure and temperature (Ref. 36-21-00) and the position of the different valves. The indicating system also shows the bleed-air duct leaks that the leak detection system finds (Ref. 36-22-00). The primary indications are shown on the lower ECAM display unit (Ref. 31-67-00) and the upper ECAM display unit (Ref. 31-66-00). Indications are also shown on the AIR COND panel 30VU. 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址:A320飞机维护手册 AMM PNEUMATIC 气源 2(102)