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A320F : minimum equipment to START RNP approach.

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A320F : minimum equipment to START RNP approach.

Old 22nd Feb 2019, 22:34
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A320F : minimum equipment to START RNP approach.

If you are operating the A320 family you should be familiar with the fact that the required equipment to start an RNP approach is listed in PRO-SPO-51. ( which happens to be : One FMGC ‐ One GPS ‐ Two IRS ‐ One MCDU ‐ One FD ‐ One PFD on the PF side , Two FCU channels , 2 NDs ) .
My question is the following : Why does airbus use the wording “start” (minimum equipment required to start RNP APCH operations) ?
Is there an implication that once you are in the procedure and you lose one of those systems you could continue under some circumstances?
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Old 22nd Feb 2019, 23:08
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You might have visual references shortly after commencing the approach. Cleared to continue!
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Old 23rd Feb 2019, 00:37
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If you have one GPS at the start of the approach but subsequently lose it you will complete the procedure prior to the nav accuracy degrading beyond limits. The rest of the items likely are required all the way down (except maybe an IRS or ND? )
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Old 23rd Feb 2019, 03:36
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Our QRH lists equipment required to start the approach, different from what you’ve described incidentally, then goes on to list the action required in the case of further failures. For some you can continue the approach, for others you can’t.
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Old 23rd Feb 2019, 09:31
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Originally Posted by alexious85 View Post
If you are operating the A320 family you should be familiar with the fact that the required equipment to start an RNP approach is listed in PRO-SPO-51. ( which happens to be : One FMGC ‐ One GPS ‐ Two IRS ‐ One MCDU ‐ One FD ‐ One PFD on the PF side , Two FCU channels , 2 NDs ) .
My question is the following : Why does airbus use the wording “start” (minimum equipment required to start RNP APCH operations) ?
Is there an implication that once you are in the procedure and you lose one of those systems you could continue under some circumstances?
Hi,

worth a read getting to grips with Required Navigation Performance with Autorization Required. Generally speaking after passing the FAF a go around is required for (less) different reasons than before crossing it.
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Old 23rd Feb 2019, 14:31
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Originally Posted by Australopithecus View Post
If you have one GPS at the start of the approach but subsequently lose it you will complete the procedure prior to the nav accuracy degrading beyond limits. The rest of the items likely are required all the way down (except maybe an IRS or ND? )
RNP APCH or RNP AR? Big difference.

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Old 24th Feb 2019, 17:35
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The list in SPO 51 lists the same equipment as the list on the QRH under “Required Equipment for RNAV Procedures”. On the QRH you can see it says “Before IAF”. For loss of equipment after crossing the IAF you can check FCOM-NOR-SOP-18-C “Management of degraded navigation”.

Remember that you only need to check those lists (particularly the one on the QRH) if you lose equipment after dispatch. For deferred equipment, the MEL will tell you your applicable restrictions.
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Old 24th Feb 2019, 18:17
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Originally Posted by Escape Path View Post
The list in SPO 51 lists the same equipment as the list on the QRH under “Required Equipment for RNAV Procedures”. On the QRH you can see it says “Before IAF”. For loss of equipment after crossing the IAF you can check FCOM-NOR-SOP-18-C “Management of degraded navigation”.

Remember that you only need to check those lists (particularly the one on the QRH) if you lose equipment after dispatch. For deferred equipment, the MEL will tell you your applicable restrictions.
Very true, I had a "slip" in my post above, it is the IAF, not the FAF.
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Old 24th Feb 2019, 21:54
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Originally Posted by Escape Path View Post
The list in SPO 51 lists the same equipment as the list on the QRH under “Required Equipment for RNAV Procedures”. On the QRH you can see it says “Before IAF”. For loss of equipment after crossing the IAF you can check FCOM-NOR-SOP-18-C “Management of degraded navigation”.

Remember that you only need to check those lists (particularly the one on the QRH) if you lose equipment after dispatch. For deferred equipment, the MEL will tell you your applicable restrictions.
What if you are radar vectored for RNAV APP?
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