Message Name:

PACK PERFORMANCE

The temperature of an aircraft zone (cockpit, forward cabin, aft cabin) cannot be kept comfortable (zone temperature is too hot).

• Pack inlet temperature sensor
• Pack temperature sensor
• Pack inlet pressure sensor
• Pack inlet flow sensor
• Pack discharge temperature sensor
• Anti-icing pressure sensor
• Mix manifold temperature sensor
• There is a mechanical failure or a performance degradation of the air cycle machine
• Pack/duct interface is disconnected or there is high leakage
• Blockage in the condenser/reheater
• Blockage in the dual heat exchanger
• Blockage in the bulkhead check valve
• Bulkhead check valve
• There is a leak in the internal distribution system
• There is a defective ventilated temperature sensor

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

Notice To Operators (NTO): None

Flight Operation Notifications Manual (FONM): None

1. Clear all EICAS and CAIMS faults related to ECS.

   1. If fault indication is gone, do close out.
   2. If fault remains, continue with next step.

2. Clear all observed faults of temperature and pressure sensors.

   1. If fault indication is gone, do close out.
   2. If fault remains, continue with next step.

3. Use the PMAT to access CAIMS System Diagnostics. Select ATA 21 > ASCS 1A (1B, 2A, 2B) > LRU TEST > PACK TEMP. SENSOR DATA. Record sensor data using the ECS data table. Compare values between channels and sides.
   NOTE: Best results are obtained if Air Conditioning system components are allowed to reach ambient temperature.
4. Make sure all temperature and pressure sensors meet their tolerances (see ECS data table).
5. If sensor values do not permit to identify faulty component, check the Air Conditioning system lines, valves and components for leakage.
6. Do close out.