(b)
Connect the quick-disconnect test fitting of the alternate static system to the static cutoff valve through the static system test gage and flow restrictor.
NOTE: You will find the test fitting on the left side of the
____ airplane above the system drains at STA 400.
(c) Open the static cut off valve.
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747-400 MAINTENANCE MANUAL
S 865-218
CAUTION: DISCONNECT THE STANDBY AIRSPEED INDICATOR AND THE STANDBY
_______ ALTIMETER FROM THE ALTERNATE STATIC SYSTEM. YOU CAN CAUSE DAMAGE TO THE STANDBY AIRSPEED INDICATOR.
(7) Do a test of the alternate static system (full-range).
(a) Apply pressure to the alternate static system equivalent to 25,000 |200 feet of altitude (11.10 |0.10 in. Hg absolute).
CAUTION: HOLD THE PRESSURE, AS AN ALTERNATIVE, BEHIND THE CUTOFF
_______ VALVE DURING THE CUTOFF TIME. YOU CAN CAUSE DAMAGE TO THE EQUIPMENT WHEN YOU OPEN THE CUTOFF VALVE WITHOUT THE PRESSURE.
(b)
Close the static cutoff valve to the system when the instrument shows the necessary altitude.
(c)
Stop for 5 to 6 minutes to permit the system to become stable.
(d)
Write the altitude.
(e)
Stop for 1 minute and read the altitude again.
(f)
Make sure that the altitude does not go down by more than 400 feet (0.20 in. Hg).
S 845-219
(8)
Open the static cutoff valve.
S 865-289
(9)
Put the alternate static system to ambient pressure.
NOTE: You must release the pressure from the cutoff valves slowly.
____
S 845-220
CAUTION: DO NOT DISCONNECT THE PNEUMATIC TEST SET WHEN THE PITOT-STATIC
_______ SYSTEM IS NOT AT AMBIENT PRESSURE. YOU CAN CAUSE DAMAGE TO THE EQUIPMENT.
(10)
Disconnect the pneumatic test set from the test fitting.
S 845-221
(11)
In the flight compartment, install the static hose to the standby airspeed indicator.
S 845-222
(12)
Install the standby airspeed indicator into the instrument panel (P2) (Ref 34-13-01/401).
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747-400 MAINTENANCE MANUAL
S 845-223
(13)
In the flight compartment, install the static hose to the standby altimeter.
S 845-224
(14)
Install the standby altimeter into the instrument panel (P2) (Ref 34-13-02/401).
S 845-495
WARNING: FAILURE TO REMOVE THE VINYL ADHESIVE TAPE FROM THE STATIC
_______ PORTS BEFORE FLIGHT MAY CAUSE LARGE ERRORS IN AIRSPEED SENSING AND ALTITUDE SENSING SIGNALS, WHICH MAY LEAD TO LOSS OF SAFE FLIGHT.
CAUTION:_______MAKE SURE THAT YOU REMOVE ALL OF THE PIECES OF TAPE. THE SYSTEM WILL NOT OPERATE CORRECTLY WHEN THE TAPE IS IN ITS POSITION.
(15)
Remove the vinyl adhesive tape from the left and right alternate static pressure ports.
S 845-226
(16)
Examine the alternate static pressure ports for unwanted materials and rough locations on the inner and outer surfaces.
TASK 34-11-00-795-228
12. The Left Dedicated Static System Leak Test__________________________________________
A. Standard Tools and Equipment
(1)
Adapters
(a) Static port test adapter - NAVAIDS, P/N 33410LH-125-4 (1 required)
(2)
Pneumatic Test Set
(a) Vacuum source, 0 to 30 inches of mercury (absolute)
(3)
Gages
(a) Static system test gage - required to indicate 0 to 30 inches of mercury (absolute) with accuracy of |0.1 (readable to |0.01) inch of mercury or |200 (readable to |20) feet.
(4)
Flow restrictors, control valves, and cutoff valves as required.
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本文链接地址：747-400 AMM 飞机维护手册 导航 NAVIGATION 1(53)
