LOGANAIR has poured cold water on suggestions that the airline could simply switch from Sumburgh to Scatsta to help islanders avoid incoming car parking charges at Shetland's main airport.
There are also calls for Shetland Islands Council to more actively support the north mainland airport by allowing it to operate commercial scheduled flights.
But Loganair chief executive Jonathan Hinkles said the idea was not worth any detailed investigation as it was clear from the outset that it would result in a poorer and more expensive air service.
Hinkles said Scatsta was licenced to operate oil industry flights only and to move to an operation with scheduled commercial flights would require very different security arrangements.
"For any airport to accommodate commercial scheduled services on seven days a week, there has to be real investment in security equipment and ongoing staffing for both the airport operator and the airline," he said.
"If implemented at Scatsta, this would simply duplicate existing resources in place at Sumburgh, massively increasing the overall costs of supporting Shetland's external air services.
"Just as importantly, Scatsta is ten minutes further flying each way to and from Aberdeen than Sumburgh. The extra operating costs of fuel and aircraft maintenance charges would have to be reflected in higher fares than those at Sumburgh.
"Moreover, the geography of Scatsta airport means that aircraft performance can be limiting and it may not always be possible to carry a full load of passengers and commercial baggage on flights to and from there depending on weather conditions and the type(s) of aircraft deployed both today and in future."
The chief executive said that resolving these two constraints would inevitably result in higher airfares.
"It's a concept that deserves to be aired, but on preliminary review, the prohibitive costs and practical barriers are quickly evident," he said.
"We haven't calculated the exact costs - but no calculator is needed ascertain that the cost for every single customer would be several leagues higher than HIAL's proposed car parking charges at Sumburgh."
He added that was also no guarantee that car parking at Scatsta Airport would continue to be free.
Representatives from Shetland Islands Council will raise again the lack of an impact assessment for the proposed Sumburgh car parking charges when they meet with HIAL management on Wednesday next week.