Can a Plane on a Treadmill Take Off?

What is keeping the airplane's speed up with the conveyor belt? The
propeller. Said propeller moves air. Air causes lift

By that logic, a pilot doing a full static runup at the runup area will
levitate.

-Robert, CFI

LOL :-)) Or do an Indian rope trick! ;-)

"Doug" posted the exciting message
oups.com:

What is keeping the airplane's speed up with the conveyor belt? The
propeller. Said propeller moves air. Air causes lift. The problem is
more complicated than it seems to be at first read.



Well, if it only took the propeller then you could set the brakes, apply
full power, and lift off at zero ground speed.

"jesse" wrote:

when you walk on a treadmill, do you have any significant
airspeed(minus wind and fans)? you are moving forward relative to the
treadmill belt only, your airspeed is zero, sure your legs are moving
at say three miles per hour, and the treadmill belt is moving three
miles per hour the opposite way, but without airspeed you have no
lift(assuming your arms were airfoils). its not that complicated
people. the thrust of the airplane is only used in most cases, to
provide a movement of air over the wings to cause lift. if the supposed
airplane is stationary to the air, regardless how much thrust is being
used to "keep up" with the treadmill, no lift will be created, try it
with an rc plane on a real treadmill if you dont believe me. Im not
calling anyone stupid, but didnt everybody learn in PP ground school
that ground speed has nothing to do with airspeed and the associated
lift? thats one of the first things, the most basic of things that i
was taught. im done with this topic. enjoy, let the roasting begin!
Jester
PP-ASEL
A&P

some people apparently have a hard time reading.

"a conveyer belt that moves in the
opposite direction at exactly the speed that the airplane is moving
forward."

When the conveyor belt is moving backwards at 80mph, how fast is the
plane moving? Hint: there is no mention of how fast the plane is
moving relative to the conveyor belt. If the plane is moving forward
at 80mph, is it likely to have enough airspeed to fly?

If you are still confused, when the plane is moving forward at 80mph,
the conveyor will be moving backwards at 80mph, and a speedometer that
measures off of tire rotation would indicate the plane's speed (before
getting airborne) as 160mph, the speed relative to the conveyor.
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.

and a speedometer that
measures off of tire rotation would indicate the plane's speed (before
getting airborne) as 160mph, the speed relative to the conveyor.

While an airspeed indicator would indicate zero.

-Robert, CFI

"Robert M. Gary" wrote:

and a speedometer that
measures off of tire rotation would indicate the plane's speed (before
getting airborne) as 160mph, the speed relative to the conveyor.

While an airspeed indicator would indicate zero.

-Robert, CFI
Only if there is an 80 mph tailwind.
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.

No. The plane is moving forward at 80mph. The wheels are the only thing
feeling the 160mph effect of the treadmill. This isn't a ground propelled
vehicle.

--
-------------------------------
Travis
"Robert M. Gary" wrote in message
ups.com...
and a speedometer that
measures off of tire rotation would indicate the plane's speed (before
getting airborne) as 160mph, the speed relative to the conveyor.

While an airspeed indicator would indicate zero.

-Robert, CFI

"cjcampbell" wrote:
Saw this question on "The Straight Dope" and I thought it was amusing.

http://www.straightdope.com/columns/060203.html

Seems Cecil Adams is compounding the confusion by having the page's title
begin:

"An airplane taxies in one direction...."

So is the plane attempting to taxi or take off? The page's title says one
thing, the person posing the question is stating another. The hypothetical
pilot of the taxing plane would presumably not let the the airspeed go to
takeoff speed, while the pilot of the plane taking off would want to
accelerate to rotation speed. So on that basis alone, we can say a taxing
plane isn't going to take off!

;-)

Taxi is just nomenclature for the airplane moving along the ground.
"Takeoff run" would be more correct I guess, but in this case things
are so weird, as it is ambiguous whether the plane is going to takeoff
or not.

If the treadmill is stationary and the belt speed is equal
to the required take-off speed, the airplane will have zero
airspeed if it is "moving" in relation to the belt, the
airplane is moving, the prop has thrust and is balancing the
rearward movement of the belt. The tires are rolling, but
the airplane is stationary and there is no airspeed or lift.



--
James H. Macklin
ATP,CFI,A&P

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"Doug" wrote in message
oups.com...
| Taxi is just nomenclature for the airplane moving along
the ground.
| "Takeoff run" would be more correct I guess, but in this
case things
| are so weird, as it is ambiguous whether the plane is
going to takeoff
| or not.
|