NOTE: With an air conditioning pack inoperative or OFF, isolation valve closed, and anti-ice OFF, a BLEED OFF LIGHT may illuminate during any phase of flight. This is most likely to occur during takeoff due to high engine power settings combined with low bleed air demands. Under these conditions the PRSOV is regulating air pressure so that the engine bleed air valve is nearly closed and the light switch is activated. As engine power is reduced, bleed air pressure is reduced and the valve opens far enough to extinguish the BLEED OFF LIGHT.
EICAS STATUS MESSAGES
None
PLACARD
Pack Control Selector as appropriate - L (R) PACK INOP
REPAIR INTERVAL
ITEM
21-51-2 Pack Flow Control/Shutoff
Valves
1) Hi Flow Mode C
C
C
EICAS STATUS MESSAGES
None
PLACARD
Pack Control Selector as appropriate - L (R) PACK INOP or HIGH FLOW MODE INOP MAINTENANCE (M)
1. Place Pack Control Selector on P5 panel corresponding to inoperative flow control/shutoff valve to OFF.
2. Gain access to valve through ECS access door (193CL or 194CR).
3. Close valve per instructions near manual actuator nut.
CAUTION: DO NOT USE EXCESSIVE FORCE ON MANUAL ACTUATOR NUT. IF RESISTANCE IS FELT
ACTUATOR DAMAGE MAY RESULT.
4. Close ECS door.
5. Notify dispatch that left (or right) pack is inoperative and flight will be limited to FL350 or below.
Flow Control and Shutoff Valve Installation
OPERATIONS (O)
With one pack inoperative, limit altitude to FL 350 or below.
When dispatching with empty Cargo Compartment the associated Compartment must remain empty or
contain only ballast, empty cargo handling equipment (ballast may be loaded in ULDs(Unit Load Device)), or Flight Kits. The content of a Flight Kit is defined in B757 Technical File. Materials to be used as ballast shall be non-combustible (see MEL Preamble).
REPAIR INTERVAL NUMBER INSTALLED
ITEM NUMBER REQUIRED FOR DISPATCH
REMARKS OR EXCEPTIONS
21-51-3 Pack Temperature Control
Systems C 2 1 One may be inoperative OFF for an associated inoperative pack.
1) Auto Mode C 2 0 May be inoperative provided associated Standby
Mode operates normally.
2) Standby Mode C 2 0 May be inoperative provided associated Auto
Mode operates normally.
EICAS STATUS MESSAGES
None
PLACARD
Pack control selector as appropriate - AUTO (STBY) PACK CONTROL INOP
B757 - 200 MINIMUM EQUIPMENT LIST
EICAS STATUS MESSAGES
None
PLACARD
As directed in MAINTENANCE (M) procedure MAINTENANCE (M)
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