Decision to commence a take off

[b737air]

Hi guys!

Here is something I am confused about:

According to EU-OPS (or PART-OPS; not sure about the name) it states at CAT.OP.MPA.180 Selection of aerodromes — aeroplanes that

(c) The operator shall select two destination alternate aerodromes when:

(1) the appropriate weather reports and/or forecasts for the destination aerodrome indicate that during a period commencing one hour before and ending one hour after the estimated time of arrival, the weather conditions will be below the applicable planning minima; or

(2) no meteorological information is available.

AND a after a few pages at CAT.OP.MPA.245 Meteorological conditions — all aircraft says that:

(a) On IFR flights the commander shall only:

(1) commence take-off; or

(2) continue beyond the point from which a revised ATS flight plan applies in the event of in-flight replanning,

when information is available indicating that the expected weather conditions, at the time of arrival, at the destination and/or required alternate aerodrome(s) are at or above the planning minima.


So, if you cannot take off when the weather at destination is below the planning minima, what it's the point of choosing 2 alternate aerodromes? :confused:
Because when the weather at destination is above planning minima at +/-1hr ETA, you only need 1 alternate.

[JeroenC]

It says and/OR. So, if an alternate (or two) is/are needed you are only allowed TO when that alternates meets its planning minima.

[b737air]

Thank you Jeroen! Seems like I put to much accent on the "destination" word and didn't pay enough attention to the "and/OR" phrasing.

[parkfell]

Put the academics to one side just for the moment, and think in practical terms just what the regulations are saying. You need a bolt hole at all times which you can comfortably escape to if your (planned) world starts to implode.

Take that one stage further, and hope for the best, but plan for the worst.

I can recall many moons ago when I was flying up to Sumburgh, Shetlands (LSI)in a Shorts 360, with previous drop offs at Inverness, and Kirkwall.

Planning TAF had LSI as CAVOK all day. Update at INV ~ NOSIG. Latest actual obtained at KOI now giving BKN 007. Uhmm I thought. Shift in the surface wind. :(. Arrived to be greeted by 300m FOG. :ugh:
As the weather up north can be fickle even at the best of times, it kept you on your toes. That combined with VOR approaches at KOI (now ILS) made life somewhat interesting at times. The wind could also be sporty at times:E