ashill

Except that’s not the way physics works. Mach 0.99 takes a lot more than 16% (0.14/0.85) more energy than Mach 0.85, in part because if the speed of the airframe is Mach 0.99, there will be significant amounts of air passing the wing at more than Mach 1. For example, the airfoil effect relies on the air on top of the wing going faster than the air below the wing, creating lift. I’m a physicist, not an engineer (to say the least!), but my understanding is that a lot of the engineering in a supersonic plane is to minimize the amount of air that’s going much faster than other air to lessen this problem. But as long as you’re in the transonic regime, the energy requirements will be much higher than the marginal gain in speed. Just not cost effective unless you’re getting supersonic, where there are more than marginal gains in speed. (And, of course, if you’re using much more energy, the carbon footprint — a cost to the airline and therefore the consumer as well as the planet — is much higher; why bother for a marginal gain?)

Back to AA, they say in the press release that they only have to accept the planes if (paraphrasing) the design makes AA happy. We haven’t seen the contract, but that strongly suggests to me that AA’s commitment to this is pretty minimal. If the design comes through, AA’s got their order in and a place in line, but it doesn’t sound like it’s much skin off their back if, as expected, this isn’t flying in a commercially-viable way any time soon. And I’m sure Overture is more than happy to sell places in line for a pittance just for the press attention.