In the late 2000s to early 2010s, rising fuel prices coupled with economic crisis resulted in cancellation of many ultra-long haul non-stop flights.  As fuel prices fell and aircraft became more economical the economic viability of ultra long haul flights improved. 
Direct flights and non-stop flights are often confused with each other. Starting March 31, 2019, American Airlines started offering non-stop flights from Phoenix, Arizona to London, England,  meaning that the plane leaves Phoenix Sky Harbor International Airport and lands at Heathrow Airport. Whereas a direct flight simply means that passengers would not get off the plane, but the plane may stop between the two cities.
- "From Newark Over the North Pole". New York Times. 30 March 2001. Retrieved 1 April 2016.
- A new era of 'ultra-long-haul' aviation
- "American Airlines first flight between Phoenix and London takes off". Chamber Business News. 1 April 2019. Retrieved 1 April 2019.