Why do planes cause vibrations on the ground as they fly pass?

[autodidude]

And vehicles on the ground as well, in particular heavy ones like trucks. How do the ground and windows to vibrate?

 

[davenn]

a question in return to help you...

what is it that aircraft and other heavy machinery have in common ?
they all emit lots of the same stuff... what is it ?
Answer that and you have pretty much answered your own question :)

cheers
Dave

 

[davenn]

did you figure that out yet ? :)

 

[autodidude]

Noise/sound waves...oh, I see

Thank you :p

 

[davenn]

Noise/sound waves...oh, I see

Thank you :p

yup you got it ! ... loud noise lots of vibrations

cheers
Dave

 

[Bobbywhy]

If you are near a large airport and are located underneath the landing pattern of the jetliners then you have heard the noise they make. When a heavily loaded passenger jet is coming in for a landing there is a description that pilots sometimes use. They say "flying down the glide slope is like a controlled crash." What do they mean by that?

A jetliner flies well at altitude at around 500 mph. Note that up there the wheels are up. Now, for landing this same jetliner has to slow down to around 140 mph with its wheels down. To keep the aircraft stable at this slow speed and high drag flaps are used.

Flaps are hinged surfaces mounted on the trailing edges of the wings to reduce the speed at which an aircraft can be safely flown and to increase the angle of descent for landing. They shorten takeoff and landing distances. Flaps do this by lowering the stall speed and increasing the drag.

During this “controlled crash” the pilot must increase the engine power settings to overcome all the drag and to keep the aircraft flying in a stable descent. This means any citizen who happens to be underneath as the jetliner passes by is going to feel the vibrations from the engines operating at high power.