Flightpath,
I'm not sure where different holds exist for different wake catergories - i've been very fortunate, I've operated around the globe but never come across it happening either operationally or regulatory. Is there somewhere it does exist that you have been looking at?
There are NO UK stacks that exist for for specific wake vortex categories. If there are I'm now going to be liable for significant cost in curries and beer
With regards to flying of the G/S. Various 'old wives tales' exist in relation to this. I can only offer you my experience. NO ONE deliberately flies beneath the G/S once established - heavies or otherwise.
Neither does intentioanlly flying high on a G/S take place for several reasons:-
1. Ones doesn't always know the wake votex category of the aircraft ahead. One might guess, but doesn't necessarily know unless visual etc (IMC?).
2. Most intermediate approaches these days are flown with the autopilot engaged. It's accurate, it's efficient, it provides minimum flight deck workload which in turn produces other monitoring/management benefits. There's not an autoplilot in the world that can say fly 'one dot high' down the G/S. If we all flew slightly above the profile of the preceding aircraft, for 'possible' vortex reasons, we would very rapidly all be on 'ex shuttle' arrival profiles (no, not BA type shuttles
).
I'm sure you'll get far more professional and qualified responses than my own, especially from UK validated ATCO's, but from a pilots perspective, I really don't have a problem, and struggle to understand the environment one wishes to create where suddenly it may exist. The LTMA is of course one of the most densely 'traffic' populated areas that exists....
Brgds
30W