Just to clear the air on this (so to speak!).
'The Buran spacecraft (Russian: Буран, "Snowstorm" or "Blizzard"), serial number 11F35 K1, was the only fully completed and operational (Russian) space shuttle vehicle.
Like its American counterpart, the Buran, when in transit from its landing sites back to the launch complex, was transported on the back of a large jet aeroplane. It was piggy-backed on the Antonov An-225 Mriya aircraft, which was designed for this task and remains the largest powered aircraft in the world.'
Source: Wikipedia