bolmas. Seems no one answered your question?
Brittain Norman produced a turbine BN2T Islander, usually termed a Defender, which had Allison 250-B17C turbine engines and Hartzell three bladed props, but in other respects, was the same as the Lycoming piston engine powered 260 and 300 HP Islander (two blade props) - although some later Defenders may have had the longer Trislander nose installed?
I'm in Australia so can't confirm what you may have seen in UK skys. The Defender was never very popular in this part of the world, but I did see one in Asia some years ago. Whilst there is a place in aviation for the STOL Islander, there is also a rumour the Islander is Britain's revenge on the colonies!
The gas turbine engines were similar to the Bell 206 helicopter engine. They were also fitted to another aircraft we don't care to think too much about, the Australian built GAF N22/N24 Nomad.
