Originally Posted by
Check Airman
Hi all,
2 questions if you would
1- we’re usually taught that when changing a value (not mode) on the FCU/MCP, to verify that the new value is reflected on the PFD, and not just the FCU. Has anyone ever seen a situation where the PFD and FCU values are different?
2- A320 specific- When aligning the IRU’s, some people do 1-2-3, and others do 1-3-2. Is there any system-related reason that the order should matter? I remember this being discussed at one point, but I couldn’t find the thread.
Thanks for the replies.
As we know Airbus knobs or anything like gear or flaps even are electrical switches not mechanically connected. So it's not enough you put switch on but also need to be check that it has worked e.g. Bulb or fan in a room has started. The chance of getting a different value on FMA/PFD may not be there but the particular switch not affecting the change at all is there. Like pulling ALT is a desire expressed but it needs to be confirmed that the aircraft is doing what was asked. Sometimes you need to pull again.
As far as IRU being switched 1,2, 3 has no systemic issue but to drive it into subconscious the fact that IR3 is in the middle. Because otherwise when dealing with abnormals you may swich off IR3 instead of IR2.