"Final" wake vortex?. .LL ATCO here, question?. .We have been talking recently about the application of wake vortex spacing at LL when crossing behind heavy traffic to get on to the other runway. Early in the morning, for example, the traffic is all heavy and we are often asked to use both runways requiring some crossing over (Inevitably some traffic from the north wants the southerly runway and vice versa).
I have always interpreted our book to demand the application of "Final Approach" w/v spacings when crossing behind traffic onto the other runway, even if still on "Base Leg" i.e. not actually on Final Approach. Irrespective of what the book actually says, it seems to me to be a most sensible precaution to apply Final Approach w/v spacings once the lead aircraft has begun to configure for the Final approach.
However, I now discover that not all agree and some ATCOs only apply Final spacing when actually on final. Having discussed the matter with many and varied it seems that our book is not absolutely clear on this point. I was wondering what our pilot friends thought on the issue. What do you think you are getting and what do you think you should get? If I am wrong then it is legal to cross a LR35, 3 miles behind a B757 at the same level for the other runway, when I would have to use 6 miles if approaching the same runway.
Anybody care to comment?
Point 4