The Tu-4 was a Soviet reverse-engineered B-29 Superfortress, of which around 15 were acquired by China in the early 1950s to form the country's first strategic bombing force. An unknown number of these aircraft were later re-engined with turboprops whilst in Chinese service, and no fewer than two of these extremely rare machines are on display at the China Aviation Museum. 4114 was further modified with a huge fuselage-mounted radar as an AEW aircraft.