Originally Posted by
Efrem
That's a big part of why Boeing's Sonic Cruiser concept was eventually ditched .......Much better, from the airlines' point of view, to put the same technology improvements into lower fuel consumption at the speeds we fly at today. (Many FT posters got this right before Boeing figured it out.)
You do the technical staff at Boeing a disservice. Boeing understood exactly what the issues were and that the Sonic Cruiser was a non-runner. It was a creation of the Marketing Department as a spoiler when the A380 was making all the running as the future of long-haul transport, to divert attention away when Boeing had nothing to offer. Now they do.
Another factor not mentioned yet is that early jet-powered airliners used turbojet engines, whereas more recent ones use turbofans. Turbofans use less fuel for a given amount of thrust, but work best at slightly lower speeds.
Indeed. The original 707 with turbojets cruised at a higher speed, and its wing was optimised for it, you will notice it is swept more than is done on current aircraft. A DC8 with turbojets actually broke the sound barrier in a shallow dive. And fastest of all was the Convair 990 (990 km/h cruising speed), but that never worked out properly and sold badly.
Turbofans came along within a year or two of the introduction of these aircraft, and were so much better that most of the original aircraft were re-engined in short order. It must have been costly but even at 1960s fuel prices it was worthwhile.