During the Second World War, new bombers flew this route. This route is no longer used, due to the advent of modern jet airliners which can fly a direct route from Canada or the United States to Europe without the need for a fueling stop. This route is longer overall than the direct route and involves an extra landing and takeoff, which is costly in fuel terms. A direct route can be efficient as it allows cruising at high altitude. A stop over on Greenland might also be possible.