DUBAI: Long-haul carrier Emirates successfully flew a Boeing 777 on a test flight Monday with one of its two engines entirely powered by so-called sustainable aviation fuel. This comes as carriers worldwide try to lessen their carbon footprint.

Flight 2646 flew for just under an hour over the coastline of the United Arab Emirates (UAE) after taking off from Dubai International Airport, the world's busiest for international travel, and heading out into the Persian Gulf before circling to land. The second of the plane's General Electric Co. engines ran on conventional jet fuel for safety.