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Interesting question this morning. My alternate has RW07/25; the ILS to 25 was U/S. TAF was for OVC007. My alternate minima are: If DH < 250 then use DH + 200. With the ILS inop, had I needed to land on 25 I would have been down to LNAV with a higher DH - if DH >=250, I need to add 400 ft. With that approach, my ceiling requirement was slightly above 700 ft.

There were predominantly easterly Winds today, but what if it is a crosswind or changeable - may I "assume" what the active runway may be and choose the "likely" one? This is about legality, not so much practicability or even safety aspects, but there aren't many viable alternates around my home airport. I can't really find an interpretation for a case such as this.

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EASA Part-CAT does not distinctly discuss unserviceable (U/S) runways when it comes to destination alternate requirements. (AMC2 CAT.OP.MPA.182 (Destination Alternates), AMC5 CAT.OP.MPA.182 (Safety Margins for Met Conditions), AMC6 CAT.OP.MPA.182 (Planning Minima)

However, AMC3 CAT.OP.MPA.182, gives information concerning the application of TAFs to pre flight planning - discussing wind speeds to be within required limits. Therefore, the planning minima requirements must concern the selection of a runway at your potential destination alternate. In other words, the TAF will determine which is the legal, active runway (for your flight plan, ETA +/- 1 hour).

For your example, if the TAF forecast easterly winds, then RWY07 can legally be assessed as the active runway in terms of planning minima AMC6 CAT.OP.MPA.182 (Planning Minima). (Or, RWY25 could be assessed if within your tailwind allowance - type/operator specific - though you probably wouldn't in this instance due to the ILS U/S).

If the planned active runway is within the safety margins for met conditions (AMC5 CAT.OP.MPA.182) and the planning minima can be met, only this one destination alternate will be required to be listed on the operational and ATS flight plan. (AMC2 CAT.OP.MPA.182(a)) Otherwise two destination alternates will be required legally to be listed on the operational and ATS flight plan (AMC2 CAT.OP.MPA.182(b)).

(What the airport operator actually determines as the actual runway in use is different from the met conditions and planning minima determination of one/two destination alternates for the IFR flight plan before you fly.)


(This answer presumes IFR flight and concerning aeroplanes, not helicopters)

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  • $\begingroup$ Thank you for that detailed answer, very helpful. I've been trying to find an equivalent in NCO, but it looks different there. NCO.OP.160 only talks about the aerodrome itself. GM2 NCO.OP.160 merely recommends to take into account e.g. surface conditions and winds. @tedioustortoise could I ask your opinion of the same question under Part NCO? $\endgroup$ Dec 9, 2022 at 14:57

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