Whilst the Tu-104 continued to be used by Aeroflot throughout the 1960s and 1970s, the safety record of the aircraft was poor in comparison to subsequent jet airliners (16 of 96 aircraft were lost in accidents). The Tu-104 was unreliable, heavy, very unstable with poor control response, with an inclination to Dutch roll. Poor design aerodynamics of the wings resulted in a propensity to stall with little or no warning and a dangerous tendency to pitch-up violently before stalling and entering an irrecoverable dive. Due to the fear of inadvertent stalls aircrew would fly approaches above the recommended approach speed, landing at , nearly faster. At least two accidents were attributed to the pitch-up phenomenon, prompting changes to the design of the aircraft and operating procedures, but the problem remained. Aeroflot retired the Tu-104 from civil service in March 1979 following a fatal accident at Moscow, but several aircraft were transferred to the Soviet military, which used them as staff transports and to train cosmonauts in zero gravity. After a military Tu-104 crash in February 1981 killed 52 people (17 were senior army and naval staff), the type was permanently removed from service. The last flight of the Tu-104 was a ferry flight to Ulyanovsk Aircraft Museum in 1986.