The Sikorsky S-22 series, named Ilya Muromets (Илья Муромец) were a series of Russian pre-WW I four-engine airliners and military heavy bombers used during World War I by the Russian Empire. It was designed by Igor Sikorsky in St.Petersburg. The last aircraft of the series were retired in 1922, but in 1970 this replica was built in the Soviet Union and added to the collection at Monino.