IFF on MEL Dispatched Aircraft
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IFF on MEL Dispatched Aircraft
I have question about Actual Landing Distance (ALD) on MEL dispatched Aircraft.
My A320 was dispacthed with SEC3 inoperative. From MMEL 2.27 P8 said that Landing distance is increased by 5%. Therefore, my actual landing distance should be (ALD from 4.03)x 1.05.
But if I've got any Inflight Following Failure (IFF) such as an Anti-skid failed. Airbus recommends to calculate
ALD (MEL+IFF) = ALD from 4.03 x MMEL penalty (1.05) x Coef Anti-skid (1.75). It is not considered as a multiple failure! Is that sound?
Back to normal aircraft without MEL, if both failures occur inflight,
ALD (IFFs)= ALD from 4.03 x Coef SEC3 (1.25) x Coef Anti-skid(1.75)
what make the difference of landing distance? MEL SEC3 proc requires switch off SEC3 PB and pull out CB which is the same as that of SEC3 inops inflight?
My A320 was dispacthed with SEC3 inoperative. From MMEL 2.27 P8 said that Landing distance is increased by 5%. Therefore, my actual landing distance should be (ALD from 4.03)x 1.05.
But if I've got any Inflight Following Failure (IFF) such as an Anti-skid failed. Airbus recommends to calculate
ALD (MEL+IFF) = ALD from 4.03 x MMEL penalty (1.05) x Coef Anti-skid (1.75). It is not considered as a multiple failure! Is that sound?
Back to normal aircraft without MEL, if both failures occur inflight,
ALD (IFFs)= ALD from 4.03 x Coef SEC3 (1.25) x Coef Anti-skid(1.75)
what make the difference of landing distance? MEL SEC3 proc requires switch off SEC3 PB and pull out CB which is the same as that of SEC3 inops inflight?
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Don't have access to a MEL, not sure if this is correct but my experience with Airbus manuals and their logic would indicate:
You don't use the failure factor because you have not had an in-flight failure. You have despatched with SEC 3 INOP which is a different situation, and is therefore treated differently.
And also as an aside:
The 5% MEL correction is at the planning stage, and I reckon it should be on RLD which is approximately 1.65 times ALD.
You don't use the failure factor because you have not had an in-flight failure. You have despatched with SEC 3 INOP which is a different situation, and is therefore treated differently.
And also as an aside:
The 5% MEL correction is at the planning stage, and I reckon it should be on RLD which is approximately 1.65 times ALD.
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Thanks TyroPicard for your sharing.
In case of SEC3 inop, MEL Landing distance penalty increase by 5%. Yes, you have to check that RLD < LDA so that the a/c can be dispatched. Once inflight , how to calculate the ALD? Isn't it the ALD from 4.03 x 1.05 from MEL?
For SEC3 MEL items, you deactivate SEC3 by push it off and pull CB out. you lost spoiler surface 1&2, your landing is 5% more.
For SEC3 Fail inflight, you switch off SEC3 .. no CB out.. you lost spoiler 1&2, you landing is 25% more!!!
Don't know if there are more inop items affected from SEC3 inflight than that of SEC3 MEL.. that's the point.
In case of SEC3 inop, MEL Landing distance penalty increase by 5%. Yes, you have to check that RLD < LDA so that the a/c can be dispatched. Once inflight , how to calculate the ALD? Isn't it the ALD from 4.03 x 1.05 from MEL?
For SEC3 MEL items, you deactivate SEC3 by push it off and pull CB out. you lost spoiler surface 1&2, your landing is 5% more.
For SEC3 Fail inflight, you switch off SEC3 .. no CB out.. you lost spoiler 1&2, you landing is 25% more!!!
Don't know if there are more inop items affected from SEC3 inflight than that of SEC3 MEL.. that's the point.
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so interesting item here, I do agree with tyropicard MEL use in planing state, it concerning RLD. But not clear when some following failure occur in flight, which correction should be used? I will use more margin for myself even it conservative.
