BSA - Block Standing Agreement.
As previously mentioned - levels to be at by - as decided between authorities.
The problem is, they are not published very well.
We get some profile guidance on the STAR plates, but these, further out restrictions you get to know by experience.
What whizzes me off is that I know the restriction is level at 270 by LIFFY - I don't want to be level 10 or 20 miles before LIFFY because it costs fuel. We are all expected to fly PLOG fuel, most of us fuel for a suitable arrival figure - say 7500kgs on an A330 in good weather, no hold, but if you have a combination of lots of pie eaters in the back, lower initial level out of departure airfield, no shortcuts etc etc, you end up a bit thin on this side of the pond and don't really want to do 270 - 20 before LIFFY
Luckily, the Shannon guys usually understand and we sort it out
