Airplane on a Conveyor Belt...

[Vraciu]

You need to watch the belt sander video Eskimo made many years ago if you don't believe an accelerating belt will apply force to a wheel sitting on it. That force is applied to the plane through the axle and landing gear and is in opposition to the thrust produced by the plane's engine and prop.

It's a fraction of the force needed to stop the plane.   The belt would need to travel at the speed of light. 

[FLOOB]

You need to watch the belt sander video Eskimo made many years ago if you don't believe an accelerating belt will apply force to a wheel sitting on it. That force is applied to the plane through the axle and landing gear and is in opposition to the thrust produced by the plane's engine and prop.

I did bruh, the other day. Prolly even watched it when eskimo posted it the first time.

[Reaper90]

You need to watch the belt sander video Eskimo made many years ago if you don't believe an accelerating belt will apply force to a wheel sitting on it. That force is applied to the plane through the axle and landing gear and is in opposition to the thrust produced by the plane's engine and prop.

The belt sander is applying its thrust to the conveyor, by way of its belt which is representative of the aircraft's tire, in order to move forward. On a conveyor belt or otherwise, I have never seen a belt sander attain powered flight. Not even when thrown in anger.

The aircraft is applying its thrust by interacting with the air to create forward motion, what the ground is doing below the tires is irrelevant. The aircraft, it's prop, and the wing only care about the air. No conveyor belt exists that can produce a high enough ground speed to impart parasitic drag on the tires of the aircraft sufficient to counteract the thrust created by even a low-powered aircraft. 

This is an exercise in silliness.

[Bizman]

Now if free rolling wheels with bearings would prevent an aircraft from taking off, planes on skis or floaters shouldn't be able to fly at all because of friction.

[Reaper90]

Now if free rolling wheels with bearings would prevent an aircraft from taking off, planes on skis or floaters shouldn't be able to fly at all because of friction.

EXACTLY.

[Vraciu]

Now if free rolling wheels with bearings would prevent an aircraft from taking off, planes on skis or floaters shouldn't be able to fly at all because of friction.

TECHNICALLY, snow and water (short of rapids) don't actively impart rearward force like a conveyer belt would.   

But the amount of speed a conveyer belt would need to even appreciably slow a plane is beyond anything I can imagine. 

[Shuffler]

You need to watch the belt sander video Eskimo made many years ago if you don't believe an accelerating belt will apply force to a wheel sitting on it. That force is applied to the plane through the axle and landing gear and is in opposition to the thrust produced by the plane's engine and prop.

I guess some have never landed a plane. The ground is moving at the same speed as the plane. The wheels touch down and the plane continues forward. You can rev up and the plane will take off. Even if the ground were moving twice the speed, the plane will do very closely to the same.

[Mar]

One of you geniuses claiming it can't take off need to try landing a plane with no wheel brakes on a moving conveyor belt with a brick wall at the end. It should slow down and stop way before reaching the wall right? I'll bring the popcorn.

[AKIron]

I guess some have never landed a plane. The ground is moving at the same speed as the plane. The wheels touch down and the plane continues forward. You can rev up and the plane will take off. Even if the ground were moving twice the speed, the plane will do very closely to the same.

Ever notice what happens to airplane tires when a jet touches down? Ever seen all the skid marks at the end of the runway? Have you ever been pushed forward in your seat when those wheels touched down? Those wheels that are not spinning (or at least not very fast)  have a rotational inertia state. To spin them up to ground speed takes force. There are many variables in this debate which is one of the reasons it was fun. Without clearly defined conditions though there will never be full agreement. Probably not even when the conditions are set in cement. Kinda like the probability question also.

[AKIron]

Think of it like this. A jetliner about to touch down is like a throttled down plane sitting on a conveyor belt. The belt has yet to spin. As soon as the tires touch down it's like the belt just spun up to 130mph. The wheels/tires have an inertia that resists being spun up. While they are skidding force is definitely being applied in the direction opposite that of thrust. The amount of force is relative to the acceleration of belt of the speed of the plane when it touches down. Imagine that force if the plane touched down at 500mph?

Remember, no brakes applied, why do the tires skid?

[Mar]

It's gonna take a long time to clean the mess off of that wall...

[morfiend]

I prefer belt sander racing to this nonsense!

  60 grit belt on a souped up portercable 4x21,it real fun till the extension cord gets pulled out.....




   

[100Coogn]

Coogan

[Vraciu]

Coogan

Direct link those who can't see the video box on your device (like me).

https://www.youtube.com/watch?v=4owlyCOzDiE

[AKIron]

You guys do realize there is a difference between matching the speed of the fuselage of the plane and matching the speed of the spinning wheels right. If you don't get that difference then you are missing half of the argument.


(if only one person can be enlightened)