Which bit of this show was implausible?
Well, reading the replies on this thread and the one in Aircrew Notices, quite a bit of the show that related to ATC and airline operation was implausible. As for the rest, I don't have a clue how plauisible it was but with the inaccuracies in the ATC part it makes you wonder.
The thing is, mid air collisions between public transport aircraft do take place - in Europe there was one last year but the previous one was in 1977. They are very infrequent. The chances of dying on a public transport flight is very remote but if you do, chances are it will because of some mechanical failure, pilot error or some religious fanatic blowing the damn thing up.
Controllers do make errors and the system is not flawless but those errors tend to lead to nothing more than brown trousers and a few sleepless nights. What's more, brown trouser incidents are getting less despite the traffic counts going up.
Despite this, the programme deliberately gave out the impression that there is a procedure in place at Heathrow that is so flawed that a collision is inevitable. It was sensationalist and unbalanced and may well put people off flying at a time when the industry is still reeling from the far more real issues thrown up by 9/11.
Of course we shouldn't be complacent. We should strive to make sure that the extremely remote threat of two airlines flying in to each other is made as small as possible. But I don't think a BBC programme designed to shock is the way to do it.