A non-stop flight in the aviation inustry refers to any flight which does not involve any intermediate stops. Many laymen mistakenly assume that a "direct flight" is similar to a "non-stop flight". An ultra long-haul non-stop flight is generally considered to be one of more than 11000 km in route length and of over 12 hours in duration, with no intermediate stop-over point. Due to great distances flown these flights are operated via great circle route or the polar route. The longest ultra long-haul flights as of May 2007 are operated between Southeast Asia and North America.