Like bookworm I too would like to know what happens in the tower during a missed approach at LHR to ensure aircraft seperation. In the programme there was virtually no communication between the 3 ATCOs controlling the approaching and departing A/C!? I have heard a 'go around alarm' mentioned, anyone care to elaborate?
So what happens in the lead up to a possible missed approach?
As the arrivals controller, as soon as I notice, for argument's sake, an a/c not slowing down (through the final director forgetting, or the crew forgetting, or deciding to ignore the speed control, whatever the reason) I'll take some action,
I certainly would not be sitting there fat dumb and happy somehow managing to not look at my radar or out the window, idly waiting for apporach to phone me to instruct me to send it around! Tee up the one ahead, maybe get the second one to reduce to a lower speed, or slow it down to min approach speed, I'd tell the departures controller sitting next to me that it would be tight, so if he had a possibly conflicting departure, he could send it straight ahead if airborne, or keep it on the runway. If it was looking like he wouldn't get a landing clearance, I'd see if I could switch one or the other to the other runway. In any situation like this, Arrivals and Departures co-ordinate very closely. It cannot be any other way.
Like has been said above, the only realistic way this could happen is if the go around is unannounced, goes radio fail and flies straight ahead instead of the missed approach procedure,
AND a conflicting departure switches over to TMA without being told to, or also goes radio fail,
AND TCAS for some reason doesn't function.
Gonzo.