For heaven's sake! Since the OP is from 'Taiwan', why on earth are we wasting space talking about A340's doing visuals at LHR
When was the last airliner 'visual circuit' flown there - anyone?
For the record, if
I had a comms failure in a visual circuit (that's 2 emergencies for some....
) the VERY LAST THING I would
want to do was to fly some ding-bat missed approach for a procedure I haven't got anywhere near to and carefully manoeuvre myself back into busy airspace and possible IMC without comms