The LGW aircraft are mainly the older 747's that VS have and may require more tlc than a newer one. I did VS to Orlando in Nov 2008 and were 3 hours late leaving (inbound a/c was late in from Las Vegas) and on the return leg had both LGW bound 747's on the ground in Orlando at the same time. Can normally pick up this flight on 'magic box' and it is often this late.