Why was the Boeing SST numbered "2707"? Boeing worked its Supersonic Transport (Boeing SST 2707) design in the 1960s. They gave it the number "2707". Why was this aircraft given that number? Did it have some significant inside-Boeing relation to the B707 or was it just some number that followed another Boeing numbering scheme?
The planned cruise speed was Mach 2.7 so I always assumed 2707 was a combination of Mach 2.7 and the then current Boeing 707.