T-34B Mentor US Navy customBeechcraft T 34B Mentor wood airplane model. The first flight of the T 34 was on December 2, 1948, by Beechcraft test pilot Vern Carstens. The United States Air Force ordered three test aircraft, which were given the designation YT 34. A long competition followed to determine a new trainer, and in 1953 the Air Force put the T 34 into service as the T 34A Mentor, while the United States Navy followed in May 1955 with the T 34B. T 34A production ran