Dirk85 has raised a great example.
CAT.POL.A.230 (f) is clearly relevant in this case. Putting everything into plain English: if there is only one runway, and you need a specific headwind component to land on it because in still winds your ODP performance shows it to be too short, you have to ensure that your landing performance allows you to comply with the requirements of
CAT.POL.A.230 Landing (a) - (d) before commencing the approach.
Why only this one case? If you're airborne, and in every other case we can supposedly disregard the requirements of (a) - (d), what is the benefit of applying those requirements in this one case? Why would the requirements of
(a) - (d) apply to only that one, specific situation?
My understanding remains that Performance Class requirements takes precedence over
CAT.POL.A.105 (a)(1), and the requirements of
CAT.POL.A.230 Landing (a) - (d) are applicable. In the case outlined in
(f) I believe that this is merely reinforcing the requirements as in that specific situation a given wind component is required in order to ensure the necessary commercial safety factors; and these factors, most pertinently the 50% HW component, are applicable.
I've not seen a convincing argument against how I've comprehended this part of IR-OPS, but I'll add the caveat that I have made being wrong into an art form...
