The "viability" is primarily driven by the airfield (Galway Airport) potentially not being available to Executive Helicopters after 31/12/15 when the current operators lease expires.
Galway County Council has voted unanimously in favour of a motion blocking the use of Galway Airport for the provision of air services to the Aran Islands after 15 December.
Last I head the current operator refused to extend services beyond 30 September, is that still the case?