will it take off?

[BillyP]

Let me see if I can explain why I don't think a normal plane will take off under this scenario.

There's a plane on the runway. It has a conveyor belt under the wheels. When the plane wheels start to roll, the conveyor goes in the opposite direction. We all agree on this, I think.

You're standing at one of the plane's wing tips but off the conveyor. The plane revs up and starts moving forward. The conveyor kicks in and moves in the opposite direction. The wheels spin faster and faster but the conveyor does too. You're still at the plane's wing tip because the wheels nor plane hasn't had any forward travel, relative from where you're standing.

The plane doesn't have any air blowing across it's wings, other than what's created by the props or jet engines.

The way I see it is, the plane can only take off if it has enough lift created from the air speed of the prop or jet engine over the wings.

I can't see a normal plane taking off. Unless there's enough wind speed created by the spinning conveyor, to create a substantial wind speed.

 

[HTWT]

You're standing at one of the plane's wing tips but off the conveyor.

You are stationary relative to the plane but not the ground or whatever the plane was stationary relative to before it began to move. The convayor only moves in response to the plane moving. You have just became a wing rider. Good luck.

 

[BTDT]

You're standing at one of the plane's wing tips but off the conveyor.

You are stationary relative to the plane but not the ground or whatever the plane was stationary relative to before it began to move. The convayor only moves in response to the plane moving. You have just became a wing rider. Good luck.

Hope you have your parachute on, your gonna need it!

 

[RayH]

Ray
The answer is yes. We transmit between ground and planes or between planes at the speed of lignt, not the speed of sound.

You are correct about the transmission speed but what about the sound coming from the speaker to your ears? Its traveling the speed of sound. If you are going faster, how can you hear it?

 

[RayH]

Let me see if I can explain why I don't think a normal plane will take off under this scenario.

There's a plane on the runway. It has a conveyor belt under the wheels. When the plane wheels start to roll, the conveyor goes in the opposite direction. We all agree on this, I think.

You're standing at one of the plane's wing tips but off the conveyor. The plane revs up and starts moving forward. The conveyor kicks in and moves in the opposite direction. The wheels spin faster and faster but the conveyor does too. You're still at the plane's wing tip because the wheels nor plane hasn't had any forward travel, relative from where you're standing.

The plane doesn't have any air blowing across it's wings, other than what's created by the props or jet engines.

The way I see it is, the plane can only take off if it has enough lift created from the air speed of the prop or jet engine over the wings.

I can't see a normal plane taking off. Unless there's enough wind speed created by the spinning conveyor, to create a substantial wind speed.

Planes fly because of lift generated from air flowing over the flight surfaces. They fly when their AIRSPEED is high enough to produce enough lift to overcome their weight. GROUNDSPEED has absolutely nothing to do with a planes ability to fly. The only function of wheels on a plane is to allow them to move on the ground irregardless of what speed the ground is moving.

 

[BTDT]

If a plane with its wheels down is sitting on a conveyor, the conveyor is spinning faster than the speed of sound, will the plane break the sound barrier? Oh my head hurts.

 

[BillyP]

Hope you have your parachute on, your gonna need it!

Why would I need a parachute? I'm not on the plane. I'm standing 'at' the wing tip but off the conveyor. Regardless of whether I'm right or wrong on the plane taking off, I'll be standing still.

One thing I'm certain of is I won't be leaving the ground

 

[Iowachild]

Planes fly because of lift generated from air flowing over the flight surfaces. They fly when their AIRSPEED is high enough to produce enough lift to overcome their weight. GROUNDSPEED has absolutely nothing to do with a planes ability to fly. The only function of wheels on a plane is to allow them to move on the ground irregardless of what speed the ground is moving.

But you had better pay attention to groundspeed because that's how fast you get from point A to point B. Fuel burn doesn't care about your airspeed!

 

[BillyP]

GROUNDSPEED has absolutely nothing to do with a planes ability to fly

I agree there, it has nothing to do with it's ability to fly. The question is can it take off! Ground speed definitely effects the ability to take off. That is until the wheels get off the ground. Then airspeed comes in.

 

[BTDT]

Why would I need a parachute? I'm not on the plane. I'm standing 'at' the wing tip but off the conveyor. Regardless of whether I'm right or wrong on the plane taking off, I'll be standing still.

One thing I'm certain of is I won't be leaving the ground

I guess myself and the poster about you being a wing rider were both mistaken. I thought you were standing at the wingtip on the plane. In that case, you will look kind of funny standing on the ground with your parachute on watching the plane take off into the wild blue yonder without you.

 

[RayH]

I agree there, it has nothing to do with it's ability to fly. The question is can it take off!. Ground speed definitely effects the ability to take off. That is until the wheels get off the ground. Then airspeed comes in.

Once you release the brakes on a plane, the wheels spin freely, (little to no friction). Ground speed has no effect on taking off, flying or landing until the brakes are applied. Take off and flght is strictly a function of airspeed over the lift surfaces. The prop produces airspeed by pulling the plane forward, it doesnt matter what the ground is doing, if the plane is moving forward through the air, its producing lift.
Think about this. When you take off, you need to reach a certain airspeed before you leave the ground, thats why there is no ground speed indicator, only an airspeed indicator. If you need 80 knots of airspeed to lift off and you are taking off into a 20 knot headwind, you still need 80 knots of airspeed but your ground spreed is only 60 knots. To the extreme, in a huricane (say 80 knot wind) you can actually takeoff standing still (0 groundspeed).

 

[BillyP]

I guess myself and the poster about you being a wing rider were both mistaken. I thought you were standing at the wingtip on the plane. In that case, you will look kind of funny standing on the ground with your parachute on watching the plane take off into the wild blue yonder without you.

That's a possibility! Or should I say probability?

Either way, it's been fun and gets one to thinking

 

[BillyP]

Once you release the brakes on a plane, the wheels spin freely, (little to no friction). Ground speed has no effect on taking off, flying or landing until the brakes are applied. Take off and flght is strictly a function of airspeed over the lift surfaces. The prop produces airspeed by pulling the plane forward, it doesnt matter what the ground is doing, if the plane is moving forward through the air, its producing lift.
Think about this. When you take off, you need to reach a certain airspeed before you leave the ground, thats why there is no ground speed indicator, only an airspeed indicator. If you need 80 knots of airspeed to lift off and you are taking off into a 20 knot headwind, you still need 80 knots of airspeed but your ground spreed is only 60 knots. To the extreme, in a huricane (say 80 knot wind) you can actually takeoff standing still (0 groundspeed).

Yeah Ray, I get all that. It's the plane's ability to move forward that has me stumped.

Anyway, I'm not arguing with you or anyone else here cause I don't have a clue. I guess it's one of those things a person needs to see in order to believe

 

[NewToy]

The plane has to take off. If you are creating thrust with the engine there is an equal and opposite reaction mandated by basic Newtonian law, this would be flight. If you reference a fixed object next to the conveyor belt the thrust of the engine would move you forward relative to the fixed point, hence lift and you're flying. I can't understant how the "no fly" contingent cannot grasp this. The landing gear would get a workout but you are going to move relative to the ground at the same speed as you would without the conveyor less the amount of drag associated with the friction inherent in the wheel bearings and the tires. I may be completely wrong but this is how I see it happening.

John

 

[BTDT]

The plane has to take off. If you are creating thrust with the engine there is an equal and opposite reaction mandated by basic Newtonian law, this would be flight. If you reference a fixed object next to the conveyor belt the thrust of the engine would move you forward relative to the fixed point, hence lift and you're flying. I can't understant how the "no fly" contingent cannot grasp this. The landing gear would get a workout but you are going to move relative to the ground at the same speed as you would without the conveyor less the amount of drag associated with the friction inherent in the wheel bearings and the tires. I may be completely wrong but this is how I see it happening.

John

Me too. That's why they have to strap/bolt down a jet engine being tested, it's still producing thrust and will try to fly (go forward) regardless of whether it's connected to a plane or not. Same for prop engine (unless prop is removed). I'm done...(I think)

 

[NewToy]

I had a much harder time wrapping my brain around the speed of light. If you are in a space ship travelling half the speed of light and you pass a stationary light source the light should only be going 1/2 speed relative to the observer in the ship?

 

[NewToy]

Me too. That's why they have to strap/bolt down a jet engine being tested, it's still producing thrust and will try to fly (go forward) regardless of whether it's connected to a plane or not. Same for prop engine (unless prop is removed). I'm done...(I think)

Why don't they just put the jet engine on a magic conveyor belt?

 

[BTDT]

I had a much harder time wrapping my brain around the speed of light. If you are in a space ship travelling half the speed of light and you pass a stationary light source the light should only be going 1/2 speed relative to the observer in the ship?

Maybe it will just appear red or blue (Doppler effect).

 

[greenedeere]

If a frog had wings he wouldn't bump his arse on the conveyer belt.

 

[RayH]

Ok, lets try this. The plane is on the conveyor with the brakes released. You tie a rope to the plane, if you stand to the side of the conveyor and the conveyor starts moving, you can hold the plane from moving by the rope. So now the conveyor is moving but you are holding the plane still. Now someone starts the engine and the prop starts turning. The plane will start moving forward right? Eventually it will move fast enough to take off..