STOL to ISC
Many thanks for all the very interesting inputs
I think the route faces some interesting times. The plan for the helicopter is that after the 2011 season the operation will move to Lands End when the heliport will become a branch of Sainsbury's. The company will be based, and overnight maintenance will take place, at Newquay with the aircraft ferrying to/from Lands End each day and then flying 12 round trips.
It will lose its great advantage of flying from Penzance heliport, close the train terminal. In summer the two S61's operate close to max capacity with over 1000 pax carried on Saturdays. However, it has steady traffic thoughout the year with the 'shoulder' period, Spring and Autumn, being much used by senior citizens. At all times, the islanders use it as a bus, flying to Pze and back in a day for the bank, hairdressers etc. The route works as the longest serving and most used helicopter service in the world, 4 million pax carried, because it is a unique combination of the right aircraft, the right length route, the demand, the heliport location and the mild weather.
Move to Lands End and things change. The Twin Otters and Islanders currently operating from there have very much lower DOC's and offer greater flexibility. 4 pax in an Islander may or may not break even. On a 61 its a disaster. It is difficult to see how the helicopter will be able to compete except for seats available per flight - I have flown 29 pax on a return leg. Its worth mentioning, however, that the S61's also operate to Tresco, one of the Isles of Scilly, which I believe would be beyond any fixed-wing to public transport standards.
As to other aircraft, the DHC7 could apparently operate as regards runway length. Despite the example of Courcheval which we're told by Flight-Test Engineer was limited to 20 pax, I'm wondering if even the Dash 7 could operate public transport to a 600 metre runway with a steep gradient, I believe its 6%, up to the middle and then similar down for the second half with a drop onto rocks close to each end. It's different from Unst which I visited in BAH Chinook/S61's. General opinion also seems to be that it would not be economical. Phileas Fogg, did Brymon ever actually operate any service to Scillies in the Dash 7?
As regards fire cover, I wasn't aware of the twenty pax rule that Twochai mentions but the airport has always had cover for the S61 with a max of 30 pax (plus up to four babes in arms and three crew)
I doubt that a change of type to the Dornier would offer much advantage as over a thirty mile leg, speed is not of such importance.
The Bristol Wayfarer sounds interesting. Would that be the Old Bristol 'Frightener' of Silver City's Airways?
A friend has a picture of the DH86, the four engined Rapide, in front of the tower at ISC so at least one four engined airliner has flown the route.
A Jetfoil would be a possible answer. However, the resident ferry, the ageing Scillonian, only operates about seven months of each year and they have been unable to find finance to replace it so I doubt a Jetfoil would succeed.
I suspect that Ghengis probably has the eventual answer with more Twin Otters, a type that reliably flies the route now and offers eighteen seats.
I think we should all watch this space with interest