I've been studying the planes section of the AMEE database, these
posts and the ActOnCO2 Methodology document. I write below how I
understood all this.

1 - the user has to choose between domestic, short haul and long haul.
This determines some parameters, like the type of the plane, the
occupation rate, etc. So this first choice is mandatory.
2 - "domestic", "long haul" and "short haul" profile items ignore
their journeysPerYear profile item value, and take into account their
distanceKmPerYear PIvalue. To use these profile items, the front-end
application should ask the user for the distance of his flight(s) (and
nothing else), in order to retrieve the corresponding CO2 emission. It
is probably more correct to define one profile item per flight instead
of gathering all km into one profile item.
3 - On the contrary, "*, one way" and "*, return" profile items ("*"
stands for "domestic", "long haul" or "short haul") ignore their
distanceKmPerYear profile item value, and take into account their
journeysPerYear profile item value. CO2 processing is based on average
values. To use these profile items, the front end application should
just ask the user for his annual number of journeys

If somebody can confirm all this is correct, it would help. Thanks in
advance!

PS: could not attach this post to the existing "Air travel
classification" thread...

Pascal

Yes, what you say below seems accurate to me. You make
a good point about not just rolling all flights into
one item. You can have several items of the same type, e.g.
2 short haul items with different names, e.g. name=holiday to paris
and name=meeting in berlin.

Andrew
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