NUMBER REQUIRED FOR DISPATCH
2 1 REMARKS OR EXCEPTIONS
EICAS STATUS MESSAGES
None
PLACARD
As appropriate
REPAIR INTERVAL NUMBER INSTALLED
ITEM NUMBER REQUIRED FOR DISPATCH
REMARKS OR EXCEPTIONS
36-21-2 Pressure Regulating and
Shutoff Valve Closed Position Indicating System C 2 0 (M) (O) May be inoperative provided
associated valve is verified to operate normally once each flight day.
C 2 1 May be inoperative for associated inoperative
ENG BLEED Pressure Regulating and Shutoff
Valve.
NOTE: This item includes the Engine Bleed Air OFF Lights. EICAS STATUS MESSAGES
None
PLACARD
As appropriate
MAINTENANCE (M)
Verify that PRSOV operates normally:
Start engine on affected side.
Select APU or APU BLEED OFF.
Make sure the bleed air isolation valve is closed.
Select associated L/R BLEED AIR switch light to the ON position.
Observe BLEED AIR DUCT PRESS on affected side is normal (approximately 20 psi).
Select associated L/R BLEED AIR switch light to the OFF position.
Observe BLEED AIR DUCT PRESS on affected side is 0.
OPERATIONS (O)
If the left or right Pressure Regulating and Shutoff Valve (PRSOV) position switch is failed in the CLOSED position, inflight, the APU Shutoff Valve will not be commanded closed when engine bleed is turned ON. Select APU or APU bleed OFF before turning the affected engine bleed ON.
If the left PRSOV position switch is failed OPEN, for inflight operations, the APU Shutoff Valve will be commanded closed and the APU will not be available as a pneumatic source. If the right PRSOV position switch is failed OPEN, for inflight operations, the APU Shutoff Valve will be commanded closed when the bleed air isolation valve is open.
On the ground, the engine start switches override the PRSOV logic in the APU bleed air control logic and the APU can be used for engine start.
REPAIR INTERVAL
ITEM
36-22-1 BLEED Lights C
C
EICAS STATUS MESSAGES
None
PLACARD
As appropriate
MAINTENANCE (M)
Notify dispatch. Flight operations may be affected.
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