Could it have been this:
http://www.airliners.net/open.file/511441/M/
Been at Bournemouth for a year now, it's been published that it's about to take to the air again.
Maybe wrong colour though. Could have been one of the Air Atlantique Electras has been in though; right colour, right sound (an Electra is basically a Herc with a different fuselage).
http://www.airliners.net/open.file/438663/M/