An emergency medical airlift service based in Glasgow is to cover some of the most remote areas of Scotland.
The Scottish Ambulance Service already provides an airlift service
The West Coast Emergency Medical Retrieval Service is aimed at helping patients from GP-run hospitals with no physician or anaesthetist on site.
Helicopters will deliver patients with life-threatening illnesses or injuries to their nearest large hospital.
Specialist staff will be taken by helicopter to smaller hospitals as part of the 18-month, £1.59m trial.
The Glasgow-based service will cover 16 rural hospitals on the west coast, from Wigtown in the south to Stornoway in the north.
The trial service will cover three rural general hospitals and 13 community hospitals within Argyll and Bute, Lochaber, Skye and Lochalsh, Wigtown, Western Isles, Arran, Cumbrae and Kinloch Rannoch.
It will serve a population of more than 158,000 in five health board areas including NHS Highland, NHS Dumfries and Galloway, NHS Western Isles, NHS Ayrshire and Arran and NHS Tayside.
Health Secretary Nicola Sturgeon said that getting very ill patients to the intensive care they required was a major challenge.
She said: "Critical illness and injury can happen anywhere. It is therefore vital that people get rapid and expert treatment."
Ms Sturgeon added: "It will also give support to our practitioners and Scottish Ambulance Service paramedics."
Roger Gibbins, the chief executive of NHS Highland, welcomed the announcement.
He said: "This service will provide safe and secure access to highly experienced accident and emergency department specialists for people in remote communities who are seriously ill or seriously injured."