I always believed it was dependant upon which way round the crewie wound up the laggie band. That explains the reason why the crewie always walked out first!
Once the laggie band wound down the rotor wizzieness wound it up the other way. So obviously the UK helis fly in the first part of the bandiness and any garlic munching, back stabbing, frenchie things fly on the wind down.
Do I get my re-cat?