This is a good one, I say no way.
the dangling wrangler
301 - 320 of 320 Posts
Joined
·
15,364 Posts
I'm still waiting for a nay sayer to explain how the action of the conveyor on the wheels could counteract forward motion of the plane due to the thrust applied by the engines. 
No way I'm reading this entire thread. If it's been explained, then so be it, but this is how I see it.
With the plane at rest, tangential velocity of the wheel is 0 ft/s.
As the engines are fired and thrust is increased, the force applied will eventually overcome the inertia of the plane at rest.
As the force increases, the wheels turn and the center of the wheel moves forward (just like the entire plane). The center of the wheel moves forward because the wheel is rotating across the ground.
If the plane was on a conveyor belt and you increased the speed of the conveyor belt to match the tangential velocity of the wheel, there would be no forward movement of the wheel.
Therefore, there would be no forward movement of the plane. With no forward movement of the plane, there is no lift created by the movement of air across the wing. Therefore, no flight.
With the plane at rest, tangential velocity of the wheel is 0 ft/s.
As the engines are fired and thrust is increased, the force applied will eventually overcome the inertia of the plane at rest.
As the force increases, the wheels turn and the center of the wheel moves forward (just like the entire plane). The center of the wheel moves forward because the wheel is rotating across the ground.
If the plane was on a conveyor belt and you increased the speed of the conveyor belt to match the tangential velocity of the wheel, there would be no forward movement of the wheel.
Therefore, there would be no forward movement of the plane. With no forward movement of the plane, there is no lift created by the movement of air across the wing. Therefore, no flight.
Joined
·
15,364 Posts
The conveyor can't do that though, the wheels on an airplane just freewheel, the conveyor has no way to act against the thrust of the engines moving the airplane forward.
Maybe you should skim over the last few pages.
Ya, I've been thinking about this since I posted.
I was focusing on the inertia of the plane, but the conveyor moving eliminates the inertia due to the wheel friction.
The conveyor belt can't oppose the force of the engines.
Okay, talked myself out of it.
I was focusing on the inertia of the plane, but the conveyor moving eliminates the inertia due to the wheel friction.
The conveyor belt can't oppose the force of the engines.
Okay, talked myself out of it.
The wheels are not driving the forward motion of the airplane...it don't matter how fast the belt is spinning the plane it going to be pulled forward by the propeller/jet engine.
Someone said running on an exercise track...try putting a jet pack on and get on the track.
I bet you move forward...It is only motionless if it's power is derived from it's wheels. If it's propulsion is from anything else (and it always is), the track that the wheels are on had better keep up with the aircraft if the wheels are to maintain contact till take off.
Anyone having flown a plane should understand this. There are only two limits to a wing powered lift off.
And that is pretty simple. You just have to acquire enough lift before you run out of runway. Nothing else matters. Getting that lift usually involves forward movement, to increase air speed. There is an air speed lift design to each plane depending on load and air temperature. So technically the plane could lift off if the air speed was high enough with the plane sitting still. Or the conveyer belt could propel the plane fast enough to create lift with the plane stationary to the belt.
For this very simple reason, you always take off and land against the wind. We used to have an air port in Tulsa , 81st, that was very short. But with a little head wind you could make ok if you did a power stall start,, Except, when it got over a 100 degrees and no wind. As we should know in our business, hot air is thinner with less lift. It also affect the engine HP.
But back to the conveyer belt. The only effect the conveyer belt could have on the plane is if it created or counteracted air speed.
"Imagine a plane is sitting on a massive conveyor belt, as wide and as long as a runway. The conveyer belt is designed to Can the plane take off?"
If the plane starts forward motion to the ground, and the conveyer belt
exactly match the speed of the wheels, moving in the opposite direction.
The wheel would be stopped in relationship to the belt, The belt would essentially move at the same speed as the plane while the wheels stood still. When the plane reached lift off speed it would lift without every turning a wheel.
And that is pretty simple. You just have to acquire enough lift before you run out of runway. Nothing else matters. Getting that lift usually involves forward movement, to increase air speed. There is an air speed lift design to each plane depending on load and air temperature. So technically the plane could lift off if the air speed was high enough with the plane sitting still. Or the conveyer belt could propel the plane fast enough to create lift with the plane stationary to the belt.
For this very simple reason, you always take off and land against the wind. We used to have an air port in Tulsa , 81st, that was very short. But with a little head wind you could make ok if you did a power stall start,, Except, when it got over a 100 degrees and no wind. As we should know in our business, hot air is thinner with less lift. It also affect the engine HP.
But back to the conveyer belt. The only effect the conveyer belt could have on the plane is if it created or counteracted air speed.
"Imagine a plane is sitting on a massive conveyor belt, as wide and as long as a runway. The conveyer belt is designed to Can the plane take off?"
If the plane starts forward motion to the ground, and the conveyer belt
exactly match the speed of the wheels, moving in the opposite direction.
The wheel would be stopped in relationship to the belt, The belt would essentially move at the same speed as the plane while the wheels stood still. When the plane reached lift off speed it would lift without every turning a wheel.
Ya know, Jr., it's bad enough when you argue with yerself. But when ya lose those arguments, yer in REAL trouble. Be on the lookout for men in white smocks and carrying very wide "belts" with very long sleeves!Ya, I've been thinking about this since I posted.
I was focusing on the inertia of the plane, but the conveyor moving eliminates the inertia due to the wheel friction.
The conveyor belt can't oppose the force of the engines.
Okay, talked myself out of it.
Joined
·
15,364 Posts
I got bored and decided to see if we could lure more people in.
STOL (Short Takeoff Landing) CompetitionI'm still waiting for a nay sayer to explain how the action of the conveyor on the wheels could counteract forward motion of the plane due to the thrust applied by the engines.
http://www.youtube.com/watch?v=7ZW85T_1LTA
Who needs a runway? All I need is 18 feet.
http://www.youtube.com/watch?v=7_dgrBevUOw&feature=related
Any questions on what wheels have to do with lift now?
There are only four factors affecting whether a plane will fly: thrust, drag, lift and weight. Thrust and lift have to overcome drag and weight in order for a plane to fly. You do not see wheels involved in any of these factors because they simply have no involvement.
Joined
·
61,972 Posts
I have not read the whole thread...
LIFT is generated by the wings. Groundspeed has nothing to do with it. (BTW: I am a private pilot; they teach you these things in ground school).
There was a MythBusters on this a while back, and yes, they proved my statement above.
LIFT is generated by the wings. Groundspeed has nothing to do with it. (BTW: I am a private pilot; they teach you these things in ground school).
There was a MythBusters on this a while back, and yes, they proved my statement above.
301 - 320 of 320 Posts
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
