Ice Pack
"So as once happened to me: Pan Pan Pan, Request a priority approach! ATC Are you delaring an Emergency? Me No but will be in about 200Kg,s."
From an ATC POV Pan Pan Pan IS an emergency and the only way to request a priority approach due fuel (other than Mayday obviously). If you simply ask for a priority approach due fuel you won't get it. It may be that if you ask, there is no holding and no expected delays, but our rules are quite clear that you MUST declare a fuel emergency ( PAN or MAYDAY as appropriate ) before priority can be given. This arose because a number of airlines took the p**s and used " a bit short of fuel " to avoid holding.
Hope this clarifies!