Fuel flow.
Cost is the other problem. It drives the aircraft price well beyond the £300k kind of range, into the category where most punters expect pressurisation and club seating with a cocktail bar, which is why we don't have any SE unpressurised turboprop IFR tourers; the marketing men then load up the airframe with gizmos, grow it in size so it can carry the extra weight and you have a Meridian or similar... shame really. The Grob 140 looked very interesting but Grob felt they had to justify the price by loading it with pricey avionics and the end result was £1M which was pointless except as a military trainer.
I'd like nothing more than a turbine. Solves the huge avgas problem which one finds when going further out.
Last edited by IO540; 2nd Dec 2008 at 07:32.