PDA

View Full Version : Land Movement, or air movement?


Vfrpilotpb
12th Jan 2002, 23:25
The Earth spins at 25k MPH, (I think), so into the hover on a still day we go in any helicopter, why dose the earth not leave the copter behind. Or is it carried along because of the ground effects?

My regards,

Dave Jackson
13th Jan 2002, 00:16
Oh! Oh!

You may have fired the opening shot in the war between the Centrifugals and the Centripetals.
<img src="smile.gif" border="0">

Grainger
13th Jan 2002, 00:42
Only 1000 mph if you think about it.

And only at the equator.

Multiply by Cos(latitude) to get the speed where you are.

Now you're moving at the same speed as the ground just before you lift. So why would your horizontal speed change just for lifting a few feet ?

HeliEng
13th Jan 2002, 03:55
Vfrpb,

You do start them don't you. Life must be very boring "DOWN" there at the moment!

This one could get very very silly!


"Some days you are the pigeon, some days you are the statue!"

sling load
13th Jan 2002, 04:55
VFRPB

Do you actually fly helicopters, or is this a Marx Bros routine?

Thomas coupling
13th Jan 2002, 06:25
C'mon VFR r u fishing or what????? <img src="wink.gif" border="0">

heedm
13th Jan 2002, 06:52
Actually, whenever you lift into a hover, you should notice that the eastern side of the helicopter is low in a stable hover. This is because you unintentionally put in a slight correction to make the helicopter hover between 1000 and 25000 mph to the east, to keep up with the earth.

Of course, that only happens in still air, since the wind on the earth is, on the average, very close to the speed of the ground, the correction you make for those very strong winds equals the correction you must make to keep up with the earth.

That's as silly as I'll get. <img src="tongue.gif" border="0">

inthegreen
13th Jan 2002, 08:14
That doesn't even take into account the speed that the Earth is moving around the solar system or the speed the solar system is moving around the milky way. It must be hundreds of thousands of miles an hour. Just think of all the work it takes to hover with all of that going on. You know what, I'll see you guys later. I have to go back to Just Helicopters and complain about how little I'm making.

widgeon
13th Jan 2002, 09:12
So how come the performance charts dont take this into account ?. There should really be no dead mans curve as you always have enuff speed to get translational lift. Is just helicopters still there ? thought they has sold it to a load of libel lawyers LOL. Are the prevailing winds from the east in the southern hemisphere ?.

yxcapt
13th Jan 2002, 09:35
Would time travel be possable with for or aft cyclic?

pants on fire...
13th Jan 2002, 12:16
Time travel is a distinct possibility with the Mini 500.

Well, at least transition into another dimension! <img src="smile.gif" border="0">

Travel around the globe is dictated solely by how high you go. The higher you jump, the more the world will rotate under your feet, and the further you go. In a hover you can only go a few feet, a similar effect as a human being, jumping from the ground, can only travel a few feet. Jump off the top of the barn, you'll go considerably further! <img src="wink.gif" border="0">

A helicopter (and most light aircraft) can only traverse a short distance around the globe at a single jump, because they remain close to the Earth and are constrained by Gravity and the fact the world will only move a little bit when you are close to it.

A jet moves a considerable distance because it gets so high that the effects of gravity are diminished and the world turns a greater distance and it consequently travels a greater distance.

The space shuttle goes so high that it can jump completely around the world in one bound!

This theory can be proven, by;
a). A motorcycle stunt rider can jump 35 double-decker buses if he gets high enough! Too low and he won't make the distance and he will have to take a rapid trip to hospital!

b). A ship takes forever to get anywhere, because it can't jump and is consequently shackled by the forces of gravity. A hovercraft gets a slight advantage, and thus goes further!

Of course, all of this is dependant upon your own direction of travel, relative to the direction of rotation of the Earth. Thus if you want to go somewhere in a rush, you should skip and jump to the East, and if you are going to do something boring, you might want to drag your feet and walk to the West.

<img src="tongue.gif" border="0">

Vfrpilotpb
13th Jan 2002, 17:37
To all of you,
Sorry about the lack of inteligence and my elementary maths mistake, I was very bored and very full of Bombay Blue + ice and a slice, but it's nice to see that you are all still out there, today I have the mother of all headache's, but have had a giggle at your reply's, Cheer's.
My Regards,
Peter B :) :)

Lu Zuckerman
14th Jan 2002, 23:32
If you shoot a rocket straight up the launch point will move as it is attached to the earth so if the rocket is destructed the debris will fall at some point other than the place of launch. I would assume that the rocket unlike the helicopter is flying independent of the air mass that circulates with the earth as it rotates.

Thomas coupling
15th Jan 2002, 02:47
I can testify to that, Lu, because after Nov 5th, I have to go round to my next door neighbours to pick up the pieces. And it's always the neighbour to the west <img src="confused.gif" border="0"> <img src="confused.gif" border="0"> <img src="confused.gif" border="0">

Droopy
15th Jan 2002, 03:56
I'd always assumed that the movement of the earth was entirely random and unpredictable - that's how it is beneath me when I'm in a steady hover.

Nick Lappos
15th Jan 2002, 08:03
I tested this rotation problem very carefully last Saturday night. After downing enough Jim Beam to properly arm my stabilizers, I leaned into the White Vortex Generator while holding a compass. I noted that here in the Northern Hemisphere (the Correct Hemisphere <img src="wink.gif" border="0"> ) the vortex rotational direction always supported the earth rotation theory. I also noted that the room was spinning even when flat on my back, an interesting independant correlation!

Isn't Science wonderful? I really love experimenting....

Vfrpilotpb
15th Jan 2002, 12:41
Consider this, and try it,

On a still no wind day, with "Gin"(that Word)clear sky's watch one of the big heavie's leave their vapour trail, then without moving your position fix your vision on a fixed earth point( building, tower, aerial or tree branch) to coincide with the vapour trail, then wait one minute and you can see the enviroment turn away from the vapour trail, quite simply aweinspiring!

now back to work, quite uninspiring!
:) <img src="wink.gif" border="0">

[ 15 January 2002: Message edited by: Vfrpilotpb ]</p>

Cyclic Hotline
15th Jan 2002, 22:18
Oh my God! The chem-trailers have got Vfrpilotpb now as well. <img src="eek.gif" border="0">

Next thing, he'll be abducted by aliens and NONE of these theories are worth anything then. He'll be transformed through time, space and dimensions without a care.

<img src="tongue.gif" border="0">

ShyTorque
16th Jan 2002, 00:26
Gyroscopes suffer from apparent drift. That is, they appear to drift off datum. In fact, it IS actually caused by the earth moving but the gyro staying put.

Oh no, what have I said? Gyroscopes again. Sorry chaps..... <img src="eek.gif" border="0">

Vfrpilotpb
16th Jan 2002, 13:47
Hey Cyclic,

I came across a Web site quite some time ago connected with Chem-Trails, what are those people on, they must also be involved with the Tree Huggers, and pure Earth eaters. :) <img src="wink.gif" border="0">

mvh
16th Jan 2002, 19:17
From now on everyone should hover paralell to the plane of rotation of the earth so the skids are straight in case of a hovering engine-failure... <img src="smile.gif" border="0">

t'aint natural
17th Jan 2002, 03:52
By my rough calculation the earth is moving around the sun at about 33,600 mph and rotating at the equator at about 1,000 mph. But which is the advancing side, and which the retreating? Am I doing 34,600 mph all day and 32,600 all night, or vice versa? And is the sun stationary in space, or is the solar system going somewhere, and if so, how fast, and is it a straight or a curved vector? What was the question again?

mvh
17th Jan 2002, 04:01
Don't worry about the advancing or retreating side - the earth flaps to equality. However, on a more technical issue, the advancing or retreating side depends on whether you are in the USA or Europe.