The Russians certainly gained access to a lot of Concorde's design details, but they missed some very important ones. And remember that the Brits had been working on delta winged supersonic aircraft during the 50s (The Fairey Delta 2 was the first aircraft to break 1000mph, in the mid 50s!)
IIRC (and its been a long time since I studied aerodynamics!), one of the problems of supersonic flight is slowing the air to sub-sonic speeds before it enters the engines. If you don't do this, the engines either stall, or become horrendously inefficient! Concorde had a very subtle design of its air intakes, that provided a passive method of slowing the air in supersonic flight. This mean that whilst Concorde needed afterburners (noisy and thirsty) to break the sound barrier, once it was through, the afterburners could be turned off.
The Russians missed this, and Concordski needed the afterburners running all the time it was supersonic. This had a severely detrimental effect on both its fuel consumption and its noise emissions!
The Russian 'plane was only ever used on a trans-Siberian route as a result, flying over a largely unpopulated region. Even government subsidies were unable to compensate for the horrendous fuel consumption, and it was withdrawn from service after a short period.
Biting the hand that feeds IT
