Can a Plane on a Treadmill Take Off?

I dont know what all the fuss is about. The plane will not takeoff for
the reason that the all the plane is doing is keeping stationary. In
actual fact the trust thats produced is not producing thrust, its only
compensating from the drag thats pull the aircraft back. (treadmill) in
order to take off the plane must superexceed the opposing force and
establish that trust actually does exceed drag. hence the the plane
must build up momentum (in the correct direction)

correct ?

Barry...

Ok, in relevance to Dougs post... we are both correct !!! apart from
the down wash from the small propeller, they will not be any airflowing
over the rest of the wings... why ??? Because the airplane is not
moving !!!! its only compensating for the exstreem backward force, as i
said its only standing still, and standing still doesnt get you
anywhere. you need momentium.

It however, would be possible if you have a plane with an exceedingly
small wing span, very low stall speed and a big propeller to generate a
downwash to cover the entire wing. As you know your aillerons are
situated at the outer section of the wings, if you have no downwash
over them it will stall and not turn leading to a temporary lift and
then crash.

Barry

See Custer Channel-wing [Google] and reaction controls.


"The Flying Scotsman" wrote in
message
ups.com...
| Ok, in relevance to Dougs post... we are both correct !!!
apart from
| the down wash from the small propeller, they will not be
any airflowing
| over the rest of the wings... why ??? Because the airplane
is not
| moving !!!! its only compensating for the exstreem
backward force, as i
| said its only standing still, and standing still doesnt
get you
| anywhere. you need momentium.
|
| It however, would be possible if you have a plane with an
exceedingly
| small wing span, very low stall speed and a big propeller
to generate a
| downwash to cover the entire wing. As you know your
aillerons are
| situated at the outer section of the wings, if you have no
downwash
| over them it will stall and not turn leading to a
temporary lift and
| then crash.
|
| Barry
|

even cjcampbell's version of the question and the poster at the web
site are different. if it sits on a conveyor belt that moves at the
speed the airplane does, then is the belt moving when the aiplane gets
on it, or does it start to move by it self?. if, in that exact
question, the airplane starts to move forward, the belt moves backwards
at an equal rate, but the plane doesnt care, the wheels spin at the
combined speed of the airplane and the belt, the plane keeps moving
forward, off the end of the belt and away into the sunset, it might
take a thousand years depending on the resistance of the wheels(if they
were very resistive i suppose it would move backwards, but then if that
were the case, it would never have moved at all, and everything would
still be stnading still), oops, even if you try to simplify that one,
it doesnt work, oh well... my plane will even jump its chocks if you
try hard enough. are there chocks on the belt... what about tie
downs.... is it made of a really sticky tar? OMGosh, see, everybody is
right, and everyone gets a cookie!!! we can all think for ourselves!
thats what being a human is all about!... all right.... ummm, can
someone turn this thing off so i dont keep wasting avgas trying to get
off this thing?... is it wide enought to turn around so i can get a
boost?... this is fun!

Look..... for all you people that think that the plane will take off.
Whats the point in having CAT Launching systems on aircraft carriers
priced at billions of dollars a piece... they could just pop down to
wallmart and buy a treadmill and the aircraft will not need to use any
runway what so ever........

DONT BE STUPID....

IT CANNOT BE DONE !!! IF IT CAN BE THEN SOME CLEVER BUGGER 50 YEARS AGO
WOULD OF DONE IT BY NOW..

plus, has anyone thought what will happen to that aircaraft if i does
manage to generate enough lift..... ITS GOING TO HAVE NO AIRSPEED,
stall and fall out of the sky like a brick.

Simple physics lads...

Wow, this is too hard to stay away from. New scenario. Same conveyor.
Instead of airplane, i hold in my hand a toy car with freespinning
wheels. If you can agree that thrust from the prop/turbine would be
akin to my hand pulling on the toy car then this will work. It is a
force acting outside of the conveyor. I start to pull the toy car, the
conveyor starts moving backwards at an equivilant speed. so what? my
hand is still pulling the car forward at say one MPH, the belt moves
back wards at one MPH... the belt is only putting a slight amount of
resistance on the car through the friction of the wheels, but nothing
that my hand(or prop etc) cant over come.... i keep accelerating the
car and the belt does too, the wheels see 2 X my forward speed, i can
increase this accelration until the wheel fall off, or untill the car
grows wings or whatever. if the car can accelrate with my hand, so can
the plane using thrust against the air. there it is. one of the amazing
things about this is that some very intelligent people have completely
different views of this. Have yall checked out the boards at straight
dope?

another example, say im on a skate board facing bakwards with a fan....
same thing, the fan pushes against the air and forth do go I.
weeeeeeeeee!

what force exactly does the conveyor hold you back with? the only force
i see is the friction in the wheels, and a negligible amount of power
from even a O-320 will overcome that. really... that and wind
resistance is the only force keeping you in one spot. If your thrust is
greater than that, newton prevails....

it just took me a while to sort it all out... have fun, stay up too
late!
Jester

"The Flying Scotsman" wrote in message
ups.com...
Look..... for all you people that think that the plane will take off.
Whats the point in having CAT Launching systems on aircraft carriers
priced at billions of dollars a piece... they could just pop down to
wallmart and buy a treadmill and the aircraft will not need to use any
runway what so ever........

No, they couldn't. Or, put another way, a scenario in which an airplane
launching from a carrier could remain stationary on a treadmill would rely
not on the treadmill, but on the presence of a suitable headwind. Of
course, in the presence of a suitable headwind, the treadmill is not needed.
But that's the whole point to this trick question: the treadmill is a red
herring.

DONT BE STUPID....

You should think a little harder before throwing the "stupid" word around.

IT CANNOT BE DONE !!! IF IT CAN BE THEN SOME CLEVER BUGGER 50 YEARS AGO
WOULD OF DONE IT BY NOW..

plus, has anyone thought what will happen to that aircaraft if i does
manage to generate enough lift..... ITS GOING TO HAVE NO AIRSPEED,
stall and fall out of the sky like a brick.

The airplane can't generate lift without airspeed. It's absurd to claim
that it would have "no airspeed". If it has enough lift to fly, then by
definition it has airspeed.

Simple physics lads...

Yes, it is. But the physics only give you the correct answer if you apply
them correctly.

Pete

"The Flying Scotsman" wrote:

DONT BE STUPID....

IT CANNOT BE DONE !!! IF IT CAN BE THEN SOME CLEVER BUGGER 50 YEARS AGO
WOULD OF DONE IT BY NOW..

plus, has anyone thought what will happen to that aircaraft if i does
manage to generate enough lift..... ITS GOING TO HAVE NO AIRSPEED,
stall and fall out of the sky like a brick.

Simple physics lads...


Ok, now suppose the treadmill is on the moon. . .

(ducks)

A plane on a conveyor belt takes off East Bound at 9:15am from Peoria,
Il, while a 747 on a conveyor belt takes off West Bound at the same
time from Hackensack NJ.
What time and at what point will they meet?

NEVER you morons. There is no air moving over the wings to produce any
'lift', much less any forward ground speed. I can't believe the
stupid crap that people talk about here.

"MaulePilot" wrote:

A plane on a conveyor belt takes off East Bound at 9:15am from Peoria,
Il, while a 747 on a conveyor belt takes off West Bound at the same
time from Hackensack NJ.
What time and at what point will they meet?

NEVER you morons. There is no air moving over the wings to produce any
'lift', much less any forward ground speed. I can't believe the
stupid crap that people talk about here.

There goes another one! g

Has anyone counted how many folks have fallen into this "trap"? I
wonder if those who call others "morons" as they fall in tend to have
bigger welts on their forehead when they finally get it and give
themselves a dope slap? g
--
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