Why do jets have swept wings?

[matus777]

"What do you notice when your 767 goes supersonic?"

answer: a smaller paycheck!

[KrisW]

	Quote: Originally Posted by Dan767
	Bigger flies better and faster. Most of the heavy airplanes, (747, MD11 etc.) cruise above .80 mach, while the smaller jets (MD80 series, some 737's ) are closer to to the mid .70's mach numbers. If you're in a hurry, go big.

Actually, the mid-small 727 (by todays standards) is the fastest (large. . excluding Lears, Gulfstreams. etc.)sub-sonic passenger plane built, if I remember correctly. Cruise at .81+ mach without breathing hard, "Max" speed was rated at .9 mach but the plane was faster than that. . of course at about .92-,94 Mach things got interesting with the center of pressure of the wings shifting aft and forcing you into a dive that was only recoverable in a Split-S and 25,000 feet of altitude used up. . but what the heck?? I've HEARD that they had a couple go supersonic. . .briefly. . but it's only a rumor.

As for what makes airplanes fly??? they have a healthy aversion for large land masses and pools of water. Any chance they get they get up into the air and stay there.

[Dan767]

727 in the "A" speed mode Mmo .909 mach. Tough to do. Only thing faster (in normal cruise): Convair 990.

[todhog]

http://www.dc-8jet.com/0-dc8-sst-flight.htm


Todd

[hillmanr2]

	Quote: Originally Posted by wizard
	Why they fly is an easy answer! When speed overcomes drag and lift overcomes gravity you have flight. You want to have fun get an aeronautical engineer and a pilot drunk and start a discussion on Bernoulli's Principle vs. angle of attack and downward deflection of air.

A very famous and well respected fluid dynamics's was quoted as " only god knows why airplanes fly"
Bernoulli, Newton, Coanda etc, etc. it is still the theory of flight!