I don't think there is any requirement in the Koran for people to pray while on a few-hours flight to anywhere.
He could just have well waited until he landed.
Most important, it is known that the terrorists who hijacked the 9/11 planes did their prayers before they launched their filthy jihad on the passengers.
I'm pretty sure that Muslims are required to pray five times a day, at set hours. That's why the "prayer call" sounds in places like Dearborn.