A hybrid-electric aircraft is to be flown between Orkney and Caithness as part of a plan to reduce harmful emissions in the Highlands and Islands.
US-based Ampaire will fly one of its Electric EEL aircraft on the 35-mile (56km) 20-minute flights between Kirkwall and Wick.
Seven round trips of the route are to be flown in mid-July.
The test flights are part of a project to create the "world's first zero-emission aviation region".
Highlands and Islands Airports Ltd (Hial), which operates Kirkwall and Wick John O'Groats airports, is among the organisations leading the long-term project.
It hopes to achieve zero-emission targets by replacing fossil fuels with electric, hydrogen and other low-carbon fuels at its airports and also on the aircraft serving them.
Hial's other airports include Inverness, Sumburgh, Stornoway, Barra and Dundee.
Following the flights in Scotland, the aircraft is to head for south west England for similar demonstration flights between Exeter in Devon and Newquay in Cornwall as part of a separate zero emissions regional airport research project.
Cut carbon emissions
An aim of the Ampaire's Scottish flights is to study the feasibility of flying between Kirkwall and Wick and "hard-to-reach" Highlands and Islands communities using hybrid-electric powered aircraft.
The California-based company said the technology could reduce airlines' operation costs, and cut noise pollution and carbon emissions.
The study will also examine what infrastructure would be needed, such as charging facilities, and how renewable energy could be used to power hybrid-electric aircraft.
The Electric EEL, which has been given tartan wingtips in Hial's colours, was used in an experimental flight across the island of Maui in Hawaii last year.
It also made a long distance 341-mile (549km) flight from the outskirts of Los Angeles to the San Francisco Bay area.