The fleet was further enlarged in 1972 with the Yakovlev Yak-42 tri-jet regional aircraft and in 1974 with the An-26 turboprop cargo aircraft. The route map kept expanding and the flow of traffic kept growing throughout the decade. In the middle of the 1980s, Moldovan operations received ten larger Tupolev Tu-154 tri-jet airliners, furthering the development of Moldovan aviation. At that time Moldovan aircraft flew to 73 cities in the USSR and carried over 1,000,000 passengers per year. In 1990 the first international route between Chișinău and Frankfurt was opened.