While the Tupolev did closely resemble the Concorde (amid speculation that Soviet espionage was behind the resemblance) the two planes did differ in many technical aspects. The Concorde had better range, braking and engine control but the Tupolev had vastly superior aerodynamics. The Tupolev's wings also included two small retractable canard surfaces—for generating low-speed lift—that the Concorde lacked. It was also generally perceived as less stable in flight, especially at supersonic speeds, than its counterpart.
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