The second of two Mil V-12 prototype helicopters, powered by four Soloviev D-24VF turboshaft engines. This aircraft first flew in March 1973 and was given to the Monino Museum in 1975, after the cessation of the development programme in 1974. It went on display as seen here, without a registration. Unfortunately in 2012 it was made to look like the first prototype by falsely painting it with that helicopter's registration CCCP-21142. The registration with which this second prototype actually flew during its operational life is unknown.

The Mil V-12 (NATO reporting name Homer) is the largest helicopter ever built and this example is the second prototype and last built of the type (sometimes incorrectly quoted as c/n 002). In 1975 it went on display at Monino without any registration (actual operational registration is unknown). In 2012 it was falsely painted as seen here, with the registration of the first prototype (which was still preserved at the MVZ im. Milya factory at Tomilino by 2018).
Both prototype V-12s outperformed their design specifications and set numerous world records which still stand today, Despite these achievements the Soviet Air Force refused to accept the helicopter and all development on the V-12 was stopped in 1974.