I am on the bench at a court that covers a large airport, and we see many of these cases. There is an anomaly in the ANO, in that Drunk on an Aircraft can only be dealt with by a £2000 fine at magistrates' court but is imprisonable at the Crown Court. In practice the CC almost always sentences well within magistrates' powers of six months. The real effect of this is that faced with the cost and uncertainty of a jury trial, the CPS will often drop the serious charges in return for a plea to the lesser ones. Hence serious air rage offences that would merit a shortish prison sentence as a warning to others finish up well down scale.