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(WARNING)
RED MESSAGE (CAUTION)
AMBER MESSAGE (ADVISORY)
CYAN MESSAGE (STATUS)
WHITE MESSAGE Require immediate crew attention. These messages are accompanied by flashing master warning, triple chime attenson with or without voice message or dedicated tone. Require immediate crew awareness and future crew action may be required in the form of alternate system selection or performance limitation. These message are accompanied by flashing master caution and a single chime. Indicate safe or normal system operation which require crew awareness, over and above the dark cockpit philosophy. Indicate minor failures or reduction in systems capability, which require no crew action.

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Quick Links

02/03/21

Message Overview:

Message Name:

DISAGREE / VALVE OPEN

Message Code:

B3-007678

Associated CAS:

PACK COOL AIR FAIL
(Advisory)

Reporting LRU: RAM AIR REG VLV
System Description: 21-53-00
Schematic Diagram: 21-53-00
Wiring Diagram: 21-53-01

Message Description:

The RAM AIR REGULATING VALVE is detected failed in open position.

Possible Causes:

  • Ram Air Regulating Valve (RARV) (MPE9)
  • Integrated Air System Controller 2 (IASC2) (A56)
  • Associated Wiring

Troubleshooting Tips:

Advisory Wire/ Service Bulletin:

  • AW300-21-0039 - "PACK COOL AIR FAIL" EICAS Message Posted During Descent

Forum Articles/Infoservice/Newsletter:

  • SIL LS7084-21-01 - RARV Testing Procedures Following "PACK COOL AIR FAIL" EICAS Message

The valve can be deactivated then re-activated.

When the RARV fails in the closed position with a confirmation time of 150 seconds, a PACK COOL AIR FAIL Advisory EICAS message comes on. The fault is recorded in the IASC Non-Volatile Memory (NVM) and sent to the Maintenance Diagnostic Computer (MDC).

  • The valve modulates depending on the Pack Inlet Temperature Sensor (PITS) and Hot Air Temperature Sensor (HATS), typically the valve should be in the open position on ground or low altitudes, and closed at high altitude and cooler ambient conditions.
  • Mechanical locks at the open, intermediate, and closed positions are available on the post SB100-21-01 valve; the intermediate position can be used for dispatch capability if the valve were to fail.
  • Typically related to the Cyan CAS message PACK COOL AIR FAIL.

From full closed to full open should be no more than 5 seconds.

rarv_pre-post

Quick Links:

Removal of the Integrated Air System (IAS) Controller AMM 21-31-01-000-801
Installation of the Integrated Air System (IAS) Controller AMM 21-31-01-400-801
Removal of the Ram Air Regulating Valve AMM 21-53-05-000-801
Deactivation of the Ram Air Regulating Valve AMM 21-53-05-040-801
Installation of the Ram Air Regulating Valve AMM 21-53-05-400-801
Activation of the Ram Air Regulating Valve AMM 21-53-05-440-801
Standard Practices - Replace Wiring SPM 20-12-00-02
Standard Practices - Wire Repair SPM 20-12-10-02

Troubleshooting Recommendations:

For aircraft Pre SB100-21-10: If the fault is not as detailed in the AW or SIL visually inspect RARV position using table 201.

Table 201 RARV Visual Position
Air Source Position Valve Arm Position Cockpit/Cabin Temp Selector Position RARV Position Observed During PBIT
Off Dispatch Full Cold Dispatch → Half open (halfway between Dispatch and Full Open) → Full Closed → Slightly Open → Full Closed ? Full Open
Full Hot Dispatch → Half open (halfway between Dispatch and Full Open) → Full Closed → Slightly Open → Full Closed → Full Open
Norm Dispatch Full Cold Dispatch → Full Closed → Back a few degrees → Full Closed
Full Hot Dispatch → Full Closed → Back a few degrees → Full Closed
Pack Only Dispatch Full Cold Dispatch → Full Closed → Back a few degrees → Full Closed
Full Hot Dispatch → Full Closed → Back a few degrees → Full Closed
Trim Air Only Dispatch Full Cold Full Closed → then slowly going back to Full Open (by 5 degree steps, → 1 second between each step)
Full Hot Dispatch → Full Closed → Back a few degrees → Full Closed

  1. Do Operational Test of the Ram Air Regulating Valve. Visually verify with two people that the valve opens and closes during power-on BIT check. The valve should be open on the ground.
  2. Do wiring check at RARV connector MPE9P1. Verify power, grounds, no connector or harness damage, pins and sockets for damage and drag.
  3. Manually move the RARV to full open, verify continuity on MPE9J1 pins "1" and "6" in the full open position. If you have a 28 VDC power supply drive the valve open with pins "4" + and "3" - nominal current 350 mA.
  4. Manually move the RARV to full closed, verify continuity on MPE9J1 pins "5" and "6" in the full closed position. If you have a 28 VDC power supply drive the valve closed with pins "3" + and "4" - nominal current 350 mA.
  5. Do wiring check between RARV MPE9P1 and IASC2.

    1. If system checks are good, do close out.
    2. If fault remains, continue with next step.

  6. Swap IASC1 and IASC2.

    1. If system checks are good, do close out.
    2. If fault remains, continue with next step.

  7. Replace RARV.
  8. Do close out.

50_plenum

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