If it has got to the stage where you have lost your required separation standard, and a collision seems imminent, best advice is to give emergency traffic and suggest an immediate heading based on the surveillance available.
At this stage the controller has lost positive control of the situation anyway .
Every situation is different, you can't regulate a left or right hand turn, give your controllers a framework and intelligent regulations to work within, and give them the confidence to make a decision in this scenario.
This controller has just made a large mistake by allowing the two aircraft to get into this situation, they will only be paralysed by trying to remember the other regulation/rule when they have a critical time period to make a decision. If you regulate either a left/right hand turn or climb or descend instruction (Uberlingen), they may well follow your rule but is this the best way to resolve this unique situation?
A regulation/rule may make the ANSP feel happy that they have covered off a problem but you need to remember that the idea is not to let the planes hit.
Experience = that thing you get just after you've needed it.
In this situation, the one size fits all rule hasn't been invented yet and never will be.
Last edited by max1; 20th May 2010 at 10:38.