Two A320 IRU questions
Thread Starter
Joined: Mar 2006
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From: USA
Two A320 IRU questions
Hi all,
1. When aligning the IRU's, I've heard a popular theory/technique/procedure that they should be moved to NAV in the order 1-2-3. I've also seen 1-3-2. I couldn't find any specified order written anywhere- neither in my company manuals, nor the Airbus manuals. Is this just urban myth, or is there actually something to the order in which they're powered up?
2. Let's say we're sitting at the gate with the GPU supplying power, and the IRU's aligned, and the GPU gets disconnected. Would it be ok to leave the IRU's in NAV while starting the APU, or would it be better to switch them off until the APU is up? Either way, why?
1. When aligning the IRU's, I've heard a popular theory/technique/procedure that they should be moved to NAV in the order 1-2-3. I've also seen 1-3-2. I couldn't find any specified order written anywhere- neither in my company manuals, nor the Airbus manuals. Is this just urban myth, or is there actually something to the order in which they're powered up?
2. Let's say we're sitting at the gate with the GPU supplying power, and the IRU's aligned, and the GPU gets disconnected. Would it be ok to leave the IRU's in NAV while starting the APU, or would it be better to switch them off until the APU is up? Either way, why?
Joined: Jan 2014
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From: N5109.2W10.5
Hi Check Airman,
The technique of switching 1,2,3 was taught to me also. Apparently it was to remind me that No 3 is the middle switch position to help avoid finger trouble when performing an ECAM / Checklist.
I would leave all 3 at NAV whilst the APU started. The internal battery was designed for short interruptions of power.
The technique of switching 1,2,3 was taught to me also. Apparently it was to remind me that No 3 is the middle switch position to help avoid finger trouble when performing an ECAM / Checklist.
I would leave all 3 at NAV whilst the APU started. The internal battery was designed for short interruptions of power.
Joined: Jul 2008
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From: The Ghetto
Hi all,
1. When aligning the IRU's, I've heard a popular theory/technique/procedure that they should be moved to NAV in the order 1-2-3. I've also seen 1-3-2. I couldn't find any specified order written anywhere- neither in my company manuals, nor the Airbus manuals. Is this just urban myth, or is there actually something to the order in which they're powered up?
2. Let's say we're sitting at the gate with the GPU supplying power, and the IRU's aligned, and the GPU gets disconnected. Would it be ok to leave the IRU's in NAV while starting the APU, or would it be better to switch them off until the APU is up? Either way, why?
1. When aligning the IRU's, I've heard a popular theory/technique/procedure that they should be moved to NAV in the order 1-2-3. I've also seen 1-3-2. I couldn't find any specified order written anywhere- neither in my company manuals, nor the Airbus manuals. Is this just urban myth, or is there actually something to the order in which they're powered up?
2. Let's say we're sitting at the gate with the GPU supplying power, and the IRU's aligned, and the GPU gets disconnected. Would it be ok to leave the IRU's in NAV while starting the APU, or would it be better to switch them off until the APU is up? Either way, why?
Joined: Mar 2001
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From: I wouldn't know.
Joined: Jun 2007
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From: Wanderlust
