On June 21, 1955, two defecting members of the North Korean Air force landed a North Korean YAK-18 on Seoul International Airport. Lt. General C.R. Ferenbaugh urges Vice Minister Lee Ho to relinquish the aircraft to the 5th US Air force and the Air Technical Intelligence Center, whom have the âbest meansâ for a thorough investigation on the enemiesâ (DPRK and USSR) aircraft and aeronautical industrial technique.