Cdn F/A,
Hi with the working holiday visa. You may find they will take you on as a temp. However, if a UK resident or citizen comes along they will be more favourable as they have the right to work for as long as they wish.
Are you interested in working and living in the UK for longer than the WHV allows? It is difficult unless you come in as a Highly Skilled Migrant. Anyway, I think most airlines will favour perm workers rather than temp.