The longest-ranged commercial flights are long – really long. Many people complain about “long” flights, like flying across America (about 5 hours), only to have people from New Zealand or Australia scoff as those travelers are often used to non-stop flights of 10 or 15 or even more hours. For them, the 5-hour connecting flight is just the “little” flight at the other end.
Currently, the world’s longest scheduled non-stop commercial flight is the Singapore Airlines route between Singapore and JFK in New York City (flights SQ23 and SQ24). The flight takes nearly 19 hours to complete and covers 9,537 miles (15,347km). This might not be the longest flight for much longer though, as Qantas is firmly set on launching new non-stop services from Sydney to London and New York, which would take around 20 hours.