(a) Pitot system test gage - required to indicate:
1) Pressure of 30 to 35 inches of mercury (absolute) with accuracy of |0.16 (readable to |0.03) inch of mercury or 300 |5 (readable to |1) knots
2) Vacuum of 10 to 30 inches of mercury (absolute) with accuracy of |1 inch of mercury minimum
(b)
Static system test gage - required to indicate vacuum of 10 to 30 inches of mercury (absolute) with accuracy of |0.1 (readable to |0.01) inch of mercury or |200 (readable to |20) feet
(c)
Differential pressure gage - required to indicate 10 inches of mercury differential pressure (minimum) with an accuracy of |0.010 inch of mercury.
(d)
Rate of climb indicator - indicating range of 0 to | 6000 feet/minute
(4)
Flow restrictors, control valves, cutoff valves, lines and port seal as required
(5)
G02321, Vinyl Adhesive Tape
C. Prepare for System Pressurization
(1)
See that the autopilot remains off.
(2)
Set both the captain's and first officer's static source selector valves to NORMAL position. They will remain in this position.
(3)
See that flow restrictors are always placed between cutoff valves and airplane pitot and static systems.
(4)
Connect pitot source in pneumatic test unit through a pitot control valve to a pitot system test gage.
EFFECTIVITY
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(5) Connect static source in pneumatic test unit through a static control valve to three static system test gages.
CAUTION: PITOT-STATIC PROBES ARE DELICATE INSTRUMENTS AND
_______ CRITICALLY ALIGNED ON THE AIRPLANE. EXTREME CARE MUST BE EXERCISED WHEN HANDLING. TEST HOSES AND ADAPTERS MUST BE SUPPORTED IN SUCH A WAY AS TO ADD NO EXTRA WEIGHT ON PROBES.
D. Captain's Pitot-Static System - Pressurization
(1) Prepare to pressurize captain's pitot-static system.
(a) Wet pitot-static probe adapter and connect pitot inlets of upper left and upper right pitot-static probes to pitot system test gage through flow restrictors.
CAUTION: ENSURE THAT PROBE ADAPTER IS FLUSHED WITH WATER
_______ BEFORE ATTACHING ADAPTER TO PROBE, OR PROBE AND/OR ADAPTER MAY BE DAMAGED. A SOLUTION CONSISTING OF HALF PURE ETHYLENE GLYCOL AND HALF WATER SHOULD BE USED IN FREEZING TEMPERATURES TO -40.F.
(b)
Place vinyl adhesive tape over pitot chamber drain holes in upper left and upper right probes.
(c)
Connect static probe adapters to forward set of static ports (S1) on upper right probe and aft set of static ports (S2) on lower right probe to two static system test gages through flow restrictors.
(d)
Connect flush static port adapter to right alternate static port to third static system test gage through a flow restrictor
(e)
Place vinyl adhesive tape over forward set of static ports (S1) on upper left pitot-static probe, aft set of static ports (S2) on lower left pitot-static probe and left alternate static port.
WARNING: WHEN THE STATIC PORTS ARE COVERED, MAKE SURE THAT
_______ CONDITION IS VISIBLE FROM THE GROUND. FAILURE TO OBSERVE AND REMOVE COVERINGS OVER STATIC PORTS BEFORE FLIGHT MAY CAUSE LARGE ERRORS IN AIRSPEED-SENSING AND ALTITUDE-SENSING SIGNALS, WHICH MAY LEAD TO LOSS OF SAFE FLIGHT.
CAUTION: DO NOT EXTEND THE SEALS INTO THE PITOT DRAINS OR
_______ STATIC PORTS. YOU CAN CAUSE DAMAGE TO THE SYSTEM.
EFFECTIVITY
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NOTE: Vacuum may be applied to captain's and first officer's
____ static systems through drain fittings in main electronic equipment center (using suitable adapters). Alternate static system may be pressurized through drain fitting in left crawlway (using suitable adapter). Should these options be chosen, all static ports mentioned in (c),
(d) and (e) must be sealed.
Test connectors (Ref par. 1.A.) may be used instead of
drain fittings to connect pneumatic test set.
(2) Pressurize Captain's Pitot-Static System
(a)
Make sure test equipment installation is complete and ready for operation.
(b)
For pressures below ambient, operate pitot vacuum source and control valve such that pressure in pitot systems do not start to decrease until after static systems have begun to evacuate. Pitot system vacuum should be monitored continuously during pump down.
(c)
For pressures above ambient, operate pitot pressure source and control valve such that pressure in pitot system begins to increase before static systems start to pressurize. Monitor instruments continuously.
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本文链接地址：747飞机维护手册AMM CHAPTER 34 - NAVIGATION 第34章导航1(25)
