After 50 years with ‘AS’ tail numbers, Alaska will start using AK on new deliveries Alaska Airlines has run out of “AS” tail numbers and will start using “AK” on new deliveries starting this month. The first plane with the new label – a 737-900ER registered as N224AK – is scheduled for delivery next week. FAA registration numbers are similar to a car’s license plate. In the U.S., each civilian… 1 min read April 9, 2016 Keep up with Alaska