EFFECTIVITY
ALL 01 Page 403 Apr 15/7434-11-02
STATIC SOURCE SELECTOR VALVE - REMOVAL/INSTALLATION
___________________________________________________
1. General
_______
A. There are two static source selector valves located on the flight deck. The captain's selector valve is located near the floor below the captain's auxiliary instrument panel. The first officer's selector valve is located in a similar but opposite position.
2. Remove Static Source Selector Valve___________________________________(Fig. 401)
A. Remove the three screws on face of selector valve assembly. This frees toggle guard and valve body from mounting panel.
NOTE: Selector valve body will hold its position behind mounting panel
____ since it is supported by pitot-static tubing from behind.
B. Remove mounting panel to expose body of selector valve.
C. Loosen fittings on rear of selector valve. Label each of three tubes as to their relative position on back of valve (top, center or bottom). Remove selector valve from three tubes. Cap tubes to prevent entry of foreign material.
CAUTION: CARE MUST BE TAKEN IN LOOSENING CONNECTIONS AND HANDLING THE
_______
TUBING TO PREVENT TWISTS AND KINKS.
3. Install Static Source Selector Valve
____________________________________
A. Note labels on three tubes stating whether they go in top, center or bottom fitting on back of selector valve. Remove protective covers from the tubes and check for any foreign material inside tubing. Clean as necessary.
B. Connect fittings and tubes to back of selector valve.
CAUTION: CARE MUST BE TAKEN IN HANDLING THE TUBING AND FITTINGS TO
_______
PREVENT TWISTS AND KINKS.
C. Install mounting panel.
D. Place toggle in NORMAL position.
E. Mount toggle guard in position with top two screws and install three machine screws to secure selector valve body to mounting panel.
F. Test static source selector valve.
4. Static Source Selector Valve Test
_________________________________
A. Referenced Procedures
(1)
34-11-00, Maintenance Practices (Pressurization)
(2)
34-11-00, Adjustment/Test
B. Test Static Source Selector Valves
(1)
On flight deck, place captain's and first officer's static source selector valves in ALTERNATE position.
(2)
Pressurize alternate static system (Ref 34-11-00).
(3)
Operate pneumatic test unit and static control valve to apply a vacuum equivalent to 11.10 (| 0.10) inches of mercury (absolute pressure) or 25,000 (| 200) feet of altitude to static systems as indicated on static system test gages.
EFFECTIVITY
ALL 01 Page 401 Oct 10/7334-11-03
SEE A
FWD
CAPTAIN'S INSTALLATION FIRST OFFICER'S SIMILAR
MOUNTING SCREW (3 PLACES)
SWITCH GUARD
SELECT SWITCH
A
Static Source Selector Valve - Removal/Installation
Figure 401
648604
EFFECTIVITY
ALL
701 Page 402
34-11-03
Oct 10/73
(4) When required vacuum has been reached and has stabilized in static
systems, close cutoff valve. Read and record indication on static
system gages.
CAUTION:_______ TO PREVENT INSTRUMENT/EQUIPMENT DAMAGE, VACUUM MUST BE
HELD AS A BACKUP BEHIND CUTOFF VALVE DURING CUTOFF
PERIOD. FOLLOWING THIS, CUTOFF VALVE IS REOPENED.
RELEASE OF VACUUM IS GRADUAL AND SIMULTANEOUS FOR ALL
PITOT AND STATIC SYSTEMS.
(5) After 1 minute, read and record values indicated on the static
system gage. The vacuum must not have decreased by more than 0.20
inches of mercury or an equivalent fall of 400 feet in indicated
altitude.
(6) Return alternate static system to ambient pressure. (Ref 34-11-00,
Maintenance Practices).
(7) Remove adapter and seals from alternate static port.
(8) On flight deck, place captain's and first officer's static
source selector valves in the NORMAL position.
(9) Temporarily seal S2 static ports on auxiliary 1 and 2 pitot-static
probes.
(10)
Pressurize captain's and first officer's static system (Ref 34-11-00).
(11)
Operate pneumatic test unit and static control valve to apply a vacuum equivalent to 11.10 (| 0.10) inches of mercury (absolute pressure) or 25,000 (| 200) feet of altitude to static systems as indicated on static system test gages.
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