57-1419 is the tail number of an individual KC-135R Stratotanker operated by the Arizona Air National Guard. [1] 57-1419 was built in 1957 and is the oldest aircraft in active United States military service. [2] [1] As of 2013, 57-1419 had 22,300 flight hours and was in service with the New Hampshire Air National Guard's 157th Air Refueling Wing. [1] In 2019, the aircraft was transferred to the Arizona Air National Guard. [3]