Passenger aircraft Il-18 was developed in 1957. The first flight was conducted by Il-18 July 4th, 1957. The government tests ended in 1958, after that the mass production of the aircraft started. Within the time period 1957-1959, 564 passenger aircraft were produced in total. After the end of their service, Il-18 was partially modified into the aircraft electronic radio countermeasures and radio reconnaissance. The aircraft received the code name Il-20 (NATO code 'Coot-A'). The ice reconnaissance plane Il-24N was developed on the base of Il-18 and designed to receive the information regarding the ice coverage of Arctic Ocean with the purpose of securing cargo seafaring in Arctic regions.