As far as I know, there has only been one helicopter escape in the UK - exactly 20 years ago.
In December 1987, a B206 was hijacked and used to spring two prisoners from Gartree prison, Leicestershire.
Gartree was a high security prison in those days - but the authorities hadn't anticipated escape by helicopter.
Two prisoners escaped - John Kendall, serving 10 years for organising a series of high value commercial burglaries and another serving life for murder.
I represented one of Kendall's gang at the original trial and remember it trial well for a couple of reasons, one of which is that they used a very simple - almost comical - method to steal large quantities of booze and tobacco from cash & carry warehouses in night time burglaries all over the South East. They had a long run, until an underworld informant tipped off the police.
The pilot was
Uncle Ian of
'Age Discrimination' fame.