will it take off?

[SeymourBota]

2 pages to this thread yesterday and 7 (or more) today!!! This could set a record.

So, I need expert commentary on this:

Normally, the engine(s) move the entire plane (and consequently the entire wingspan) through the air- even while still on the ground and not generating enough lift to fly.

In this scenario, the entire wingspan does not get to move, but rather air is drawn over it in 1,2 or 4 (or however many) points an engine exists.
Would the question not be whether the engine(s) can generate enough airflow over their localized portions of the wing to generate lift- sufficient to support the whole plane?

I have no idea how much a jet engine, for example, can generate in localized air flow, but a heck of alot is necessary over a long wing to lift a heavy jet.

A smaller, lighter prop driven plane with a large engine(s) and aggressive-pitch prop(s) seems like it would stand a better chance of creating enough airflow over enough wing area to generate the lift necessary to counter the weight of the plane, allowing it to take off.

 

[MrJimi]

There should be nothing to this.
Because a Plane WILL NOT fly without airspeed and on a treadmill? Ya wont have that.
FAA licensed Pilot and Instrument rated!!
Ask any pilot, bring on the pilot replies
Jim

 

[755inNY]

What gear is the plane in? Is it gas or diesel? What rpm is it tacking? Does it have R-1 or R-3's? Is it 4x4 or just 2wd? These answers might give us something serious to think about...
David from jax

You missed another very important consideration. Is the transmission manual or hydrostatic?

Jeff

 

[jwnge]

All I know is I ain't standin in front of that plane when the pilot revs up the engine....

 

[DieselPower]

I have been thinking about this for a few day's now. My answer is no, the plane would not take off. There would not be sufficient lift on the wings to raise the plane. If the plane is not moving there is no lift.

 

[jwstewar]

Why does everyone keep missing the point the plane will be moving? It isn't driven by the wheels. The prop/jet engine propels it. Again the wheels will just spin faster. If the plane lifts at 300 MPH then the wheels will be doing 600 MPH but the wings and the rest of the plane will be doing 300 MPH.

 

[DieselPower]

That's just the point, the plane is not "moving". It does not matter how fast the wheels are turning, how fast the prop/jet is spinning, it is on a convyer belt that is moving backwards. The plane is stationary in one point in 3D space with no forward movement. So I say again, no forward movement, no lift, no it would not lift off.

edited to add the origina question:

"a plane is standing on a movable runway( something like a conveyor).as the plane moves the conveyor moves but in the opposite direction.the conveyor has a system that tracks the speed of the plane and matches it exactly in the opposite direction.

the question is

will the plane take off or not?"

 

[shaley]

Well how do planes fly in a wind tunnel. That plane is sure sitting still just like the palne on the conveyor and they fly.
Did you look at Uler's equation. Rhymes with boiler not ruler.

 

[Tom_Veatch]

All I know is I ain't standin in front of that plane when the pilot revs up the engine....

You are a wise man! Otherwise you would surely be run over when the a/c moves forward in response to the thrust of the engine(s) as the tires freewheel against the conveyor belt. (also an FAA Instrument Rated pilot)

BTW, usually the transmissions are manually controlled but hydraulicaly actuated - hydrostatic(?). However, I once owned a 1954 V-35E Bonanza which had a geared transmission. (To you pilots who think I've flipped out, I'm talking about the propeller pitch control, which serves somewhat the same function as the transmission in a ground vehicle. Uhhh..Make that "tractor". Now we're back on topic. )

 

[RayH]

Sense we were having so much fun debating the finner points of tire pressure in the other thread....

i thought this would be kinda fun...

a plane is standing on a movable runway( something like a conveyor).as the plane moves the conveyor moves but in the opposite direction.the conveyor has a system that tracks the speed of the plane and matches it exactly in the opposite direction.

the question is

will the plane take off or not?

(ps its been debated to death on other forums, its always fun to see how people present the theory behind there answer)

Yes, the plane will take off. The conveyor (runway) is matching the planes speed but it doesnt matter what the runway is doing, what matters is what the plane is doing in relation to the air.