The story of the choice of the wing planform [chord/sweep variation along span] for the Tu-144 is didactic. It is known that the development of the Tu-144 began in the USSR in 1963. Britain and France began the development of the Concorde as a joint project a bit earlier. The wing of the Concorde prototype had a so-called sinusoidal shape of the leading edge with variable sweep angles of 76-58°. It seemed that such a complex shape, which was the result of a longtime research, apparently provides some unique aerodynamic properties. In particular, it was assumed that this shape is most favorable for the formation of vortex systems and allows to reach maximum nonlinear lift increments at high takeoff and landing angles of attack. A number of our specialists had a desire to copy this shape. However, it was shown by TsAGI [Central Aerohydrodynamic Institute] and OKB [Tupolev Experimental Design Bureau] that rounding of leading edge breaks has practically no impact on the lift properties, but worsens the longitudinal static stability at large angles of attack. In addition, the Concorde wing with a large cantilevers' sweep angle had low aspect ratio.
As it is known, the wing of the Tu-144 prototype has a single break of the leading edge, consisting of straight segments in the root extension and cantilever parts with different sweep angles. The series production Tu-144 had the sweep angle of the cantilevers' leading edge increased to 57° similar to the Concorde prototype, at the insistence of the same experts. However, when the data on the series production Concorde had been published in the press, it turned out that its "unique" shape of the leading edge was changed and the cantilevers' sweep angle was reduced down to 55°, as it was on the Tu-144 prototype. It should be noted that the use of the Tu-144 experience improved the aerodynamic performance of the Concorde in all flight modes.