1. VS only have quad engined aircraft.
2. LHR were on westerlies yesterday, so heading west wwld be after takeoff (or on a go-around).
3. VS do not have any A380 (so either A340 or B747).
4. Some defects require wheels left down for a specific time interval after take off (with considerable performance implications).
5. Simonflyer, if you don't know something, it is prudent to keep quiet rather than open your mouth and be seen to be a fool.