PickyPerkins, perhaps you'd like to expand on this idea. Seperation in RVSM seems rather tight at times when the guy above is a big heavy. Unfortunately, so often, the overtaking heavy above on the same NAT track hasn't the good manners to comply with the AIC i.e. the overtaking aircraft should offset (1 or 2 miles right of track) and expects everyone else to clear his/her path/wake. I hope and pray we don't see such bullish conduct by the future A380 crews, othewise we'll need 5 miles offsets and heaven help every turboprop taxiing behind one of these giants, they'll end up doing ground loops on the taxyways from jet blast.