Firestorm,
Well the Twotter is somewhat less than 'eye candy' from a passenger point of view, once upon a time I worked for Brymon, like many of DHC's products the Twotter was designed for all the gravel strips etc. of Canada, whilst, for Brymon, it served as an ideal work horse for the ISC routes Brymon also utilised it on the BHX and EMA routes to/from Gatwick, businessman routes, and for such routes the Twotter was unsuitable, it is slow with a cruising speed of circa 150 knots and with a fixed undercarriage.
In comparison the Do228 has a significantly higher cruising speed and with retractable gear, not only does it look like more of a convential airliner, eye candy for the passengers, than a Twotter but it gets those passengers to destination quicker and, thinking commercially, an airline can achieve more utilistion, more rotations, in a lesser period of time than they can with the Twotter.
Boslandrew,
If my memory serves me correct, in the event that the ISC had been fogged out for a day or longer, I recall Brymon considering putting a DHC7 in to ISC and this was when ISC, besides a short tarmac strip for helicopters, was a grass airfield. I recall Brymon, having done the figures, would have put a DHC7 in were it not that the PLH based (solitary) DHC7 was normally utilised doing something else.
But then you're going OTT, 50 passenger seats to fill and with twice as many engines/systems as a convential aircraft of that size, and with the age of DHC7''s, I would anticipate high maintenance costs. Another problem for DHC7, whilst thay can operate to/from literally any airfield so many smaller airfields don't have the required minimum fire cover, in the old days somewhere like Biggin Hill needed to get a civvy fire appliance in to meet the minimum cover, and at cost to the airline.
P.S. I wonder if PLH's terminal roof still bears the scars of G-BRYB taxiing in to it with engines running!