To fly into - or out of - the Vagar in the Faroe Islands, you have to fly close to terrain. Unlike today, usually you can't see it. You just have to have faith in your guidance system.
The Faroes carrier Atlantic Airways has worked for ten months trialling a high-precision GPS-guided approach to Vagar under visual conditions, with fare-paying passengers on board, Finally the authorities - Denmark's civil aviation authority - have approved the system as a high-precision approach and departure aid.
We are talking about Required Navigation Performance - Authorisation Required 0.1 (RNP-AR 0.1), which is a long-winded way of saying this is a high-integrity precision GPS guidance system that will guarantee to keep your lateral position within a few metres of where you should be, but never less than 0.1nm away from it. When you are flying, on approach, departure or go-around, along a snaking valley with invisible granite walls close either side of you in the far North Atlantic fog, system integrity matters.
The crew can choose a number of alternative approaches to either end of the runway at Vagar depending on the way the wind is blowing, because terrain-related windshear matters too.
If you want to see what this is like, I have done the trip in the Atlantic Airways A319 flightdeck, and took plenty of photos.
And if you want to know what kind of a destination the Faroes can be for an aviator, there's more.
This is Europe's first RNP approach to AR 0.1 precision. Atlantic Airways pioneered it with Airbus and Quovadis. The A319 Atlantic uses is uniquely designed for the Vagar operation, with more powerful CFM56 engines than A319s normally have to enable it to clear terrain on departure even if one engine fails at V1 during take-off, and of course the specially designed nav package.