As a mere passive observer all I can say is that all the talk and bluster about how good the various ATCs are is all fine and dandy, but doesn't actually address the hard fact that what would probably have been one of the world's worst air disasters was only averted, not by these controllers at all, but simply by the fact that, thank God, the US Air FO was on the ball.
What if the Aer Lingus crew had spotted the US Air flight a couple of seconds earlier and decided that they too should stay low?
It would be unbelievable that something as fundamental as this situation could ever be allowed to happen in any airfield, let alone one of the busiest in the world.
So, what I would like to know is, exactly what measures have been introduced to prevent this ever happening again? Someone earlier suggested the adoption of the old railway controllers baton method and this was dismissed as a wind-up. But at least it is more or less foolproof. Surely there has to be some sort of analogous method?