Aer Arann ATR72 was a charter for racing at Cheltenham...they'll be back in April for the Gloucester vs Munster Heineken Cup match too...
http://thumbs.fotopic.net/732048000045.jpg
ATR 42 or Dash 8-200 or 300 are pretty much unrestricted off GLO's runway, but the Manx2 IOM route with a 19-seater really has shown the potential and exploited the niche.