Multiple faults from IASC associated with various systems.

The Integrated Air Management Controller (IASC) controls multiple systems on the aircraft. There’s a possibility of an internal failure affecting multiple systems of the aircraft at the same time. This makes it an easy target for removals and generates a higher number of NFF at the vendor level when units are removed early in the troubleshooting process.

In cases where multiple CAS messages are posted on systems that are not directly associated, we may consider the IASC as the most probable cause.

For example, CAS messages posting at aircraft power-up for the Pressurization system and the Bleed Detection System.

As a reminder, the IASC reports fault(s) for the Air Conditioning (PACK), Bleed and Pressurization systems.

When this type of fault on various systems are reported by the IASC and are posting at power-up do as follows:

• Confirm with crew or MDC timestamp that the fault occurs at the same time.
• Reset the IASC and look if both faults still post after the PBIT.
• Swap the IASC and see if the faults have transferred to the opposite side or to different systems.

If the faults transferred and the IASC is clearly identified as faulty replace it.

If the fault stays on original side the sub-system will need to be troubleshoot independently based on the reported MDC fault.

The recommendation is to find the B3 code in the MDC and carry out the troubleshooting procedure of the sub-system as per the SmartFix Plus Troubleshooting procedure associated with the MDC Fault code.