For some unknown reason (

) when operating on 09, it is very easy to suddenly have 1 or 2 too many aircraft off the stacks. Ideally, the point where the Final Director turns inbounds onto final is 12ish miles. However, this can very easily extend out to 18, 19 20 miles or more (if the INT Directors haven't quite been counting up track mileage accurately (Guilty your honour!

) or a brisk easterly wind steams them downwind) The radar manoeuvering area to the west of the field in which the EGLL approach guys have to operate suddenly becomes very cramped, and taking a flight or two "over the otherside" for ride is an excellent was of building in track miles.
I remember a Concorde pilot coming off OCK one afternoon who was taken over the field for a right-hand downwind exclaim "Wow. We don't get over this side very often"