(via) Airports – both their interiors and exteriors – represent some of the most forbidding terrain for skateboarders. They offer an endless array of modular obstacles, rails, transitions and smooth open spaces, but they are as off-limits as military installations and zoos. Which is why it’s pretty damn dreamy that – as part of an open-minded branding exercise – a group of world class skateboarders were invited by Finn Air to fly into Helsinki Airport and rip it up for two days last month — hangars, runways, blast fences, ticket kiosks, baggage claim carousels, and all. Take a look…