Aeroflot's route network had extended to by 1950, and it carried 1,603,700 passengers, of freight and of mail during the same year. Night flights began in the same year, and the 5th five-year plan, covering the period 1951–1955, emphasised Aeroflot expanding night-time operations, which vastly improved aircraft utilisation. By 1952, some 700 destinations around the Soviet Union received regular flights from Aeroflot. On 30 November 1954, the Ilyushin Il-14 entered service, and the aircraft took a leading role in the operation of Aeroflot's all-Union services. The number of passengers carried in 1955 increased to 2,500,000, whilst freight and mail carriage also increased, to 194,960 and 63,760 tons, respectively. By this time, Aeroflot's route network covered a distance of some . The 20th Communist Party Congress, held in 1956, saw plans for Aeroflot services to be dramatically increased. The airline would see its overall activities increased from its then current levels by 3.8 times, and it was set the target of the carriage of 16,000,000 passengers by 1960. In order to meet these goals, Aeroflot introduced higher capacity turbojet and turbine-prop aircraft on key domestic routes, and on services to Aeroflot destinations abroad. A major step for Aeroflot occurred on 15 September 1956 when the Tupolev Tu-104 jet airliner entered service on the Moscow-Omsk-Irkutsk route, marking the world's first sustained jet airline service. The airline began international flights with the type on 12 October 1956 under the command of Boris Bugayev with flights from Moscow to Prague. The aircraft placed Aeroflot in an enviable position, as airlines in the West had operated throughout the 1950s with large piston-engined aircraft. By 1958 the route network covered , and the airline carried 8,231,500 passengers, and 445,600 tons of mail and freight, with fifteen percent of all-Union services being operated by jet aircraft.