[mehrdadn]

> Swept wings are necessary to cruise efficiently beyond ~300mph at high altitude

Layman here, but 737, 747, etc. don't have swept wings, right? So they all cruise inefficiently... but are in fact stable... which is the opposite of what you wrote earlier? Sorry, I'm just really confused.

[stickfigure]

You're picturing a fighter jet or something with severely swept wings. Do an image search - 737s, 747s, et al do indeed have gently swept back wings. They don't stick straight out at 90 degrees like aircraft from the piston era.

[banku_brougham]

Totally off topic but I see some of those WWII era piston craft flying and its quite a nostalgic experience.

[mehrdadn]

Ohh I see, okay thanks.

[tpowell]

I like the LAX screensaver on Apple TVs—you can pick out the more organic/bird-like curve of the newer generation carbon fiber 787 planes from the old ones. I’ve never thought about it, but they do look less stable.

[AWildC182]

From a stability perspective there's likely no difference insofar as the stall response will be bad regardless. You can have complex wing geometry that stalls gracefully, for instance carbon general aviation aircraft have similar traits but require much cleaner stall response for certification generally.

BTW since it's been tossed around a lot, good stall response is when the whole wing stalls at the same time and both wings tend to stall together, therefore you get a clean lurch downward in a straight predictable line. Bad stall response is one part of one wing stalling before the rest such that the wing drops and the plane has to be fought to avoid a spin or if extreme enough, a tail slide or extreme side slip.

[dragonwriter]

> Layman here, but 737, 747, etc. don't have swept wings, right?

They do, in fact, have swept wings.