The Middle East's biggest airline will soon be operating the world's longest commercial flight.Emirates announced plans Thursday to begin daily roundtrip flights between DXB and PTY, its first destination in Central America. It says the 17 hour, 35 minute flight when heading west will be the longest anywhere, by a mere 17km. Australia's Qantas currently operates the world's longest flight, from DFW to SYD, which takes just under 17 hours. Singapore Airlines previously operated an even longer flight connecting SIN - EWR but scrapped it in 2013.Emirates is backed by the government of Dubai and has expanded rapidly by routing international transit passengers and cargo through its hub in the Gulf commercial center.The PTY flights are scheduled to start Feb. 1.