After all the hype of the Sonic Cruiser, Boeing has managed to produce a state-of-the-art aircraft in the 7E7 with a cruise speed of Mach 0.85. Already some of its design is being questioned, but with all the claimed aerodynamic improvements, it should have have been possible to achieve at least M0.9 without too much pain.
D F Newland Stanmore, Middlesex, UK
Source: Flight International