:werd: :lol:

but its not free to move cause the belt can still accelerate once the thrust kicks in. thats how it got up to speed in the first place

ok right now im thinkin that the thrust will attempt to move the plane forward but it will roll on the wheels until it gains enough speed to create the high and lwo pressure, then will attain lift... and if the conveyer moves the same speed as the plane but backwards that initial roll will not be possible... and therefore no liftoff.

until the plane reaches rotate speed it doesn't matter, there wouldn't be enough thrust to produce enough lift for it to take off. And rotate speed wont be reached because one force would be counteracted with the other one.

the thrust acts on the body of the plane. the belt acts on the wheels. two forces working on two different objects.

You're thinking of it like its a car. a car would need to out accelerate the belt to move because the wheels are what drives it. since the wheels are what is providing the thrust, the thrust can be controlled by another force acting DIRECTLY upon it (the belt) The plane is driven by the turbines which are NOT dependent on wheel speed. For the plane to be held stationary, it will need to be restrained. The belt does not act directly upon the thrust generated by the turbines, so the plane will still move forward.

ok elaborating on my post nwo im thinking that the wheels are regardless and the turbines could overcome that obstacle of the treadmill... but now im thinkign soemthing else... F thsi my head hurts!!

F THE PLANE

the belt CAN NOT affect the thrust of the turbines. they do not interact with eachother at all, not even indirectly.

the best possible example I could give you would be waterskiing from a helicopter. you can go against the flow of water and guess what, you're moving forward. the thrust of the helicopter is not affected by the direction of the water. the skis are like the wheels on the plane, they merely ride along the surface.

f the plane

i know what turbines do. I think you fail to realize that a plane must reach a certain speed to take off. if the airplane is in a belt and is moving forward and turbines are pushing it UNTIL it reaches the rotate speed it's connected to the ground! If it remains on the belt and it counteracts its advances forward that means that INDICATED, CALIBRATE, TRUE, and GROUND speed will be ZERO! a convetional airplain WILL NOT take off with a ZERO airspeed.

does the belt act directly on the body of the plane? no. does the belt act drectly on the wheels? yes. do the wheels act directly on the body of the plane? NO. Does the body of the plane act directly on the wheels? yes.

the thrust is coming from the body of the plane. the wheels begin to roll, and the belt starts to roll the opposite direction. If the wheels were driving the plane (like a car) that would be direct opposition to thrust. the only way to directly oppose the thrust of the plane would be to put the nose of it up against a wall or find some other way to restrain it.

you are still failing to tell me how the airplane will gain enough speed, it MUST roll forward to gain speed, and it will not.

The belt is not holding the plane back, the wheels are free to spin. the body of the plane will be moved forward due to the thrust generated by the turbines. the wheels will just speed up, thats all. the thrust is completely independent from the belt's input on the wheels. the belt could be going twice the speed in the opposidte direction and the plane would still take off.

to me this doesnt even make sence. before the plane takes off it is a CAR. Sure the wheels arent driven by the turbines but you need them to roll and gain speed. maybe you should go fly a plane then you'll change your mind.


**** this airplane problem

for once what iw as thinkign before.. agrees with tsar....

F the plane! And he agrees!

http://cjcfo.fbody.com/members/jeffh...illechaize.jpg

ahahahahahahahahahahahahahaha

thats the problem, it isnt a car. if it were driven by the wheels, youd be right. it doesnt directly use the wheels to increase forward speed.

Here's how I look at it.

A planes gotta have a runway for a reason. I've watched em take off, the roll aroudn at first till theyre in the lane and then the accellerate... and stay ont eh ground, rolling on the wheels until the forward motion has built up the high and low pressure areas above/below the wings that suffice for liftoff.

If a plane could just up and go like you guys are saying, wtf is the point of a runway?

the wheels on the plane are like the ones on a shopping cart, they act as rollers and nothing more. the plane is PULLED thru the air with the engines, the plane needs air speed. not ground speed to take off.

This is how I understand it: The discrepancy is the difference from the thrust of the engine and the wheels. I guess the problem arises when you have to imagine an enormous treadmill that can move hundreds of mph.

Imagine
The pilot applies thrust to the enigines (say 50%thrust - enough to get the plane to move @200mph not sure of the exact amount just a ballpark guess) the engines spool and the thrust kicks in which moves the wings then the body (collectively several dozen tons) and finally the wheels (supporting the entire weight of the plane) which rotate at 200mph as a result of the thrust applied. THe treadmill then moves 200mph in the opposite direction to compensate. 200mph plane forward - 200 mph treadmill backward=0mph which results in no lift. Without the treadmill the plane moves the 200mmph forwad. Without the thrust the plane moves backwards @ 200mph

Remember the weight of the plane is the connection between the the engines' thrust and the wheels.

thats not what we're saying, did you read this thread?

the plane does move forward and does create lift...it isnt just taking off from a standstill (like a harrier or helicopter or something)

everyone on anti-rice understood it

f the plane

FYI airspeed and ground speed are essentially the same. Ground speed is airspeed + or - the wind speed.

:werd:

The het plane will NOT take off....... and the prop plane would take off.... no more of this thread.