(6)
Adequate length of hose to couple pressure source with pitot tubes and vacuum source with static ports or drain.
(7)
Pitot static probe adapter P/N AD-953-7 and flush static port adapter 33410LH-125-4, Nav-Aids Limited, 2955 Diab Street, Quebec, Canada H4S1M1, or equivalents.
C. Prepare to Test Air Data System
(1)
Inspect each pitot-static probe before and after this test for evidence of damage to the circular leading edge of its barrel or obstructions within the drain or static ports.
(2)
To prevent damage to equipment and instruments and to ensure valid readings, the following precautions must be observed before applying pressures to pitot static system.
CAUTION: IF THE FOLLOWING PRECAUTIONS ARE NOT OBSERVED, EQUIPMENT AND INSTRUMENTS WILL BE DAMAGED.
(a)
Turn on air data electrical power before static or total pressure hook-ups are made. Leave power on until all pressure hook-ups are vented to atmosphere. Pressure changes must be flow regulated to avoid sudden changes in pressure and possible damage to air data hardware.
(b)
Keep static pressure within the range of 3.43 to 31.02 inches Hg. Do not allow it to differ by more than 28 inches Hg. from ambient pressure. Keep total pressure within the range of 3.0 to 41.0 inches Hg.
(c)
Make pressure changes such that the rate of change of altitude is less than 3,000 feet per minute and the rate of change of airspeed is less than 300 knots per minute. Maintain static line pressure less than pitot line pressure and the difference never to exceed 10 inches Hg.
(d)
On GJ B-2509 thru B-2510, do not change setting of static source selector valve while vacuum is on static system. Ensure selector valve remains in normal position unless test procedures specify otherwise.
(e)
Ensure autopilot system remains off during test.
(f)
Ensure pitot static probe heaters remain off during test.
(g)
Connect captain's, F/O's auxiliary and alternate static systems together during this test, and apply static pressure simultaneously to all systems.
NOTE: The static pressure source connections may be made at the combined pitot-static probe static port or the static system drain fittings located in the nose wheel well and electronics bay. Connection at probe is preferred. The flush static ports (alternate static) shall be sealed off at the skin. Removal of the seals shall be complete, leaving no deposits or roughness in or about the static ports.
(h)
Connect captain's, F/O's, and auxiliary pitot tubes together during the test and apply pitot pressure simultaneously to all systems.
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Aug 01/96 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 34-12-01 Page 503
NOTE: The pitot line pressure connections may be made at the combined pitot-static probes or at the pitot system drain fittings located in the nose wheel well and electronics bay. Connection at probe is preferred.
(3)
Disconnect cabin altitude differential pressure indicator from its static pressure source and cap pressure source.
(4)
Provide electrical power.
(5)
Perform air data pressure instruments operational test.
WARNING: FAILURE TO OPEN FLAP LOAD RELIEF CIRCUIT BREAKER MAY RESULT IN INJURY TO PERSONNEL.
(6)
Open FLAP LOAD RELIEF circuit breaker on load control panel P6.
(7)
Close air data system circuit breakers on load control panels P6 and P18.
(8)
Turn altimeter BARO setting knob on captain's, F/O's and standby altimeters through
entire range, then set to 29.92 approaching from a lower number and stop without
overshoot.
(9)
Connect test set to airplane.
(10)
Verify cabin altitude differential pressure indicator on pilot's overhead panel P5, is disconnected.
(11)
On GJ B-2509 thru B-2510, verify both static source selector valves are in NORMAL position.
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34-12-01 Page 504 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. Feb 20/89
D. Test air data system
(1)
Observing all previously mentioned limitations and restrictions, apply pressures given in Table 501, Test Point No. 1. All readings should be within limits specified. Difference in reading between captain's and F/O's indicators should not exceed values shown in Table 502.
NOTE: At each test point, allow pressure to stabilize for at least one minute before readings are taken. Do not tap or vibrate indicators before test readings are taken. Read indicators simultaneously for each test point. Verify indicators move smoothly without binding or hesitation during pressure changes. 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：737 AMM 飞机维护手册 导航 NAVIGATION 1(30)
