The UK government has signalled its readiness to reserve slots at an expanded London Heathrow airport in order to establish new public service obligation (PSO) subsides for domestic routes.
It says it wants 15% of new capacity produced by the building of a third runway at the hub to be ring-fenced for services to regional points in the UK or Crown dependencies.
The subsidised routes would be exempted from air passenger duty.
Further details on the use of PSOs to protect flights between Heathrow and other specific airports are to be set out in an aviation strategy green paper later this year.
The government expects Scotland to benefit from an additional 100 flights a week to and from the airport if a third runway is built.
Plans for Heathrow's expansion will be presented to parliament for a vote later this summer.