There's some useful legal gen on the case here on
The Magistrate's Blog.
Edited to add:
Link won't work - here's the story:
Mile High Club
The Daily Mail has done a good job today in reporting the acquittal of a woman charged with drunken and indecent behaviour on an aircraft. Unlike other papers the Mail goes into the legal reasons for the acquittal; the location of the aircraft was critical, since the illegal acts had to happen over the UK for an English court to have jurisdiction. My understanding is that if the aircraft is registered in the UK then British courts have jurisdiction wherever it may be, but foreign-flagged aircraft have to be in our airspace.
There was a case a decade or more ago when a drunken American kicked off on a Pan Am flight from the Middle East to the USA. The captain landed in the UK to offload the idiot, who was arrested and held in custody. He was, if I recall aright, fined a lot of money that had to be returned to him when it was realised that with an aircraft travelling at about 600 mph nobody could be sure where it was when the trouble started. Pan Am had the last laugh though, because they sued in the American courts for the very high cost of diverting the aircraft, together with the hotel bills of the other 300 passengers.