I remember sitting on the jump seat of a departing flight ex-LHR (A320) and a few minutes after take-off our path crossed that of an A340 just above us, I would've sworn blind that it was 500 feet or less, but the TCAS showed that the vertical separation was bang on 1000 feet, which was the legal minimum. The captain chuckled that when in a hold in the same situation, that as the other aircraft turned in parallel they came closer as the measurement was from the centre-line of the hull and the wings of both the aircraft were that bit nearer.
I'm sure that both 777's were vertically separated as they should be by LHR ATC. Still, at least it kept the vacuous Kardashians of the front page for a day..
SHJ
Last edited by SpringHeeledJack; 29th May 2012 at 16:37.