LV,

Don't forget that, preferably as early in the vectoring process as possible, you are quite within your rights to ask for an "x mile final" where x is a range of your choice (without extracting the urine, of course).

Though asking for X mile final.. doesn't mean they will give it to you :)

Roffa,

Fair point. Thanks.

The 'period of stabilsed flight' (ie established on LLZ) prior to glidepath intercept varies with aircraft category and closing heading and is a UK CAA and ICAO requirement. I admit I'm a bit out of it now but in my recollection it is a minimum of 2nm.
No UK ILS procedure is authorised for glidepath intercept from above and if it happens to you, then report it to CAA or CHIRP.

In GA, I think a lot of the above-GS intercepts happen because one is given a descent to the platform and then the final (base leg) vector arrives very soon after. To make the platform altitude before reaching the localiser, one may need to descend at 1000fpm or more, but one is not going to be doing that because say -500fpm was plenty fast enough while on the previous vector, and it is only the final vector which makes the current ROD too small, but it is too late to do much about it (except do a little "DIY" heading adjustment to intercept the LOC a bit further out). I can straight away recall 2 occassions where this obviously happened.

So, chevvron, given that you and Roffa are both ATC, how does one reconcile this?