411a
Thanks.
No one here is suggesting doing anything that contravenes any regulations, be they implemented by the authority or by the company, so you must do what is required of you, sensible or otherwise.
It would appear that in the UK/Europe we operate with slightly greater flexibility at the hard end of the flight (it doesn't really matter if you're shorthaul or longhaul as the decision making process is the same) when it comes how the remaining fuel is used.
As to Avianca (into JFK), that they ran out of fuel was compounded by their poor communications with ATC as to the fuel remaining. As to QF and MH into LHR I don't know the fuel in tanks they had, but I presume that they require a minimum of 30 mins AT TOUCHDOWN, they may end up with less on stand (you can wait quite a while for a stand at LHR). So they could have landed with 30mins and arrived on gate with less. Furthermore the BA engineers at LHR will raise an Air Safety Report if you end up on stand with less than 30 mins fuel at max landing weight (which could of course differ from the reserve fuel requirements on the day). It is often the engineers ASR's that find their way into the press.
In all of this, lets not forget that while if would be (never been there myself) very uncomfortable landing with less than 30 mins fuel, it is still fuel that is usable for the day that the best plans don't quite work out.