Lucifer/jtr - there's a high speed airway in eastern Siberia that has a min. speed of .84 or .85 (can't remember the exact speed), so it's effectively limited to 747s.
Despite all the whingeing from the Jumbo brigade there's not a hell of a difference in TAS between .82 and .85 - a jumbo picks up maybe 20 minutes in a 12 hour flight. Not that you'd believe it listening to all the moaning coming from the sharp end
