EU 2019/1387 changes to landing distance assessment at time of dispatch
November 7, 2019 at 1:03 pm #1959JasperParticipant
Recently the requirements changed with regard to landing performance checks at time of dispatch in CAT.POL.A.230 and CAT.POL.A.235.
In NPA 2016-11 the change is explained as follows:
“Furthermore, paragraph (f) on alternates is proposed to be deleted for the following reasons:
— the original intent of this requirement was to cater for a rare and unique set of circumstances, which is better addressed by an exemption or a derogation than a general rule; and
— this paragraph is partly superseded regarding the in-flight check part by the proposed new CAT.OP.MPA.303.
It is, however, considered that alleviation for alternates is necessary for operations on contaminated runways; in this regard, a proposal is made.”
In EU 2019/1387 CAT.POL.A.230 paragraph (f) was indeed removed (which described the exemption when you are dependant on the wind, you have to have two alternates that comply with the landing performance requirements). By removal of this paragraph it is implied that when the required performance is dependant on the wind, dispatch is not allowed anymore. This is also true for CAT.POL.A.235 when the runway is wet. For a contaminated runway however, dispatch is allowed if two alternates are available that comply with the landing performance requirements.
In appendix 5 to Opinion No 02/2019 a draft flow chart is provided (page 22) that was not incorporated in the GM. This also supports the interpretation of the change, as described above (as does the unchanged GM).
Previously it was written: “For dispatching the aeroplane it shall be assumed that:
(1) the aeroplane will land on the most favourable runway, in still air: AND
(2) the aeroplane will land on the runway most likely to be assigned, considering the probable wind speed and direction […]”
This has now been replaced by ‘For dispatching the aeroplane, the aeroplane shall EITHER:’. I would interpret this as having the choice to comply with only one of the two, instead of both. This does not make sense with the GM and the flow chart.
In addition, if the still air requirement can not be complied with, dispatch is only allowed if the runway is contaminated. This seems counterintuitive, although I understand that this results in a longer LDA that would be required that for dry or wet.
I would like to hear your thought on this, and how you interpret these changes.
Thanks and best regards,
JasperFebruary 5, 2020 at 3:45 pm #1985Duke HamParticipant
Some months ago I started to look into this and indeed it all looks very odd to me too.
Do you have an answer by now or are you still in doubt.
Why not ask EASA directly how to interpret this.
Very interesting question by the way.
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