MPN, the captain is always in the position to decline, or say "unable."
As you will note from this thread, any number of Captains who post here do that when they get such a request.
You do raise a valid point.
After I looked at some back of the napkin math in terms of the time and distance, and deceleration to stable approach asked for in the 180/5 call, I'd have to ask you this.
Doesn't the controller usually know what kind of aircraft he is tallking to? (local or not, large medium small, etc)
Does a controller have a "smart book" or "smart card" with expected approach speeds for a given heavy handy at his station?
Is the controller taught to rely on a crew telling him if they can or not?
EDIT: tilnextime. Amen. The mishap investigation we did on some unbriefed formation flying (which ended in tears) remains one of the most depressing tasks I ever got involved in.
