MEL definition
hans brinker My last post, if you'd take my word for it, was written with enthusiasm. Instead of displaying that, the resulting verbiage came out quite confrontational, nasty. Sorry about that.
Line up and with the tkof clearance turn on the LDG lights but one of them is not working: The EU rules allow you to go straight away. I understand that the US rule is to vacate at the first exit, fill the paperwork and start over. I am not entirely convinced this would actually happen.
The idea I had is that the formalist EU are not allowed to interpret the "meaning of rules" but required to stick to them at all times. Butterfly wing effect, then we try not to create rules which will be impossible to follow. (Loose reference: AC 120-71 - Effective SOP section of the document, namely Once established, the SOPs must be applied with consistency and uniformity throughout the operation).
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Line up and with the tkof clearance turn on the LDG lights but one of them is not working: The EU rules allow you to go straight away. I understand that the US rule is to vacate at the first exit, fill the paperwork and start over. I am not entirely convinced this would actually happen.
The idea I had is that the formalist EU are not allowed to interpret the "meaning of rules" but required to stick to them at all times. Butterfly wing effect, then we try not to create rules which will be impossible to follow. (Loose reference: AC 120-71 - Effective SOP section of the document, namely Once established, the SOPs must be applied with consistency and uniformity throughout the operation).
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jaja If something has changed 20 years ago, based on 40 years of previous experience and the new version is in force today, it still is 60 years of experience - combined.
You constantly refer to somebody departing with a NO GO item. Why would anyone do that?
Quoting the AMC --- that acronym actually means the mandatory and only (unless otherwise approved by the NAA) approved means of compliance --- That's an important one.
It says the MEL (OM-B section MEL) does not get approved by the NAA until a procedure for the taxi-phase is drawn and inserted there. For which a typical wording is "open the MEL and use the NO DISPATCH / DISPATCH POSSIBLE as a key to figure out whether to taxi back or go, if unsure must contact the MCC duty officer".
When you say nobody has that text, my mileage really varies. It sounds like an incomplete and non-compliant OM. I could see the NAA being at fault where you stand but not the legislation itself - proven by that very quote.
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@pinteam The two of us and hans operate the same airplane. I strongly suggest that if the MMEL says NO DISPATCH on that thing, you really do not want to fly it.
Remember, what the evaluation criteria between NO DISPATCH and RELIEF POSSIBLE are. It is the expected combined effect after another, independently caused, failure on the same system. The resulting state becomes the key. Hence you can do 1 brake inop, but not 2. Or taxi and tkof LT inop for a night - but only as long as both LDG LTs are operative.
Another example: during F/CTL controls check while taxiing already, ELAC 1 PITCH FAULT. Reset per QRH, re-action the F/CTL check (part of the QRH proc): the failure re-appears. That is a NO GO by the book. Seeing those words means the smart engineers decided the state after ELAC 1 PITCH FAULT does not have the redundancies anymore.
Compare that ELAC 1 PITCH against the case of a single PACK (go item): if the opposite would fail, you lose all pressurization sources, but the hull will contain pressure somewhat - there still is a backup in place. Touch your heart, not much of it!
Well, where it says NO DISPATCH for the ELAC 1 PTICH FAULT it means the equivalent result after a second failure would be worse than having no packs at all.
You constantly refer to somebody departing with a NO GO item. Why would anyone do that?
Quoting the AMC --- that acronym actually means the mandatory and only (unless otherwise approved by the NAA) approved means of compliance --- That's an important one.
It says the MEL (OM-B section MEL) does not get approved by the NAA until a procedure for the taxi-phase is drawn and inserted there. For which a typical wording is "open the MEL and use the NO DISPATCH / DISPATCH POSSIBLE as a key to figure out whether to taxi back or go, if unsure must contact the MCC duty officer".
When you say nobody has that text, my mileage really varies. It sounds like an incomplete and non-compliant OM. I could see the NAA being at fault where you stand but not the legislation itself - proven by that very quote.
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@pinteam The two of us and hans operate the same airplane. I strongly suggest that if the MMEL says NO DISPATCH on that thing, you really do not want to fly it.
Remember, what the evaluation criteria between NO DISPATCH and RELIEF POSSIBLE are. It is the expected combined effect after another, independently caused, failure on the same system. The resulting state becomes the key. Hence you can do 1 brake inop, but not 2. Or taxi and tkof LT inop for a night - but only as long as both LDG LTs are operative.
Another example: during F/CTL controls check while taxiing already, ELAC 1 PITCH FAULT. Reset per QRH, re-action the F/CTL check (part of the QRH proc): the failure re-appears. That is a NO GO by the book. Seeing those words means the smart engineers decided the state after ELAC 1 PITCH FAULT does not have the redundancies anymore.
Compare that ELAC 1 PITCH against the case of a single PACK (go item): if the opposite would fail, you lose all pressurization sources, but the hull will contain pressure somewhat - there still is a backup in place. Touch your heart, not much of it!
Well, where it says NO DISPATCH for the ELAC 1 PTICH FAULT it means the equivalent result after a second failure would be worse than having no packs at all.
. You are right in, I would definitely have continued the take off with one light failed, and completed the write up in the air (provided I knew the light was deferrable by the FC, and not required for the operation), a system fault would most probably be treated different. Also great words of advise about the no go items, as a recent accident shows:
Accident: Smartlynx A320 at Tallinn on Feb 28th 2018, runway excursion after bad touch and go due to elevator control completely lost
https://avherald.com/h?article=4b57c3dd/0000&opt=0
They reset the ELACs a few times, left one off, the other failed, so no sidestick input possible while hurling down the runway....
