Can a Plane on a Treadmill Take Off?

Peter, I think you lost the relative perspective. Given the original riddle,
the treadmill only moves backward at the same rate the plane moves forward.
If the plane was developing exactly enough thrust to counteract the
headwind, it will not move and neither will the treadmill.

--
-------------------------------
Travis
"Peter Duniho" wrote in message
...
"Damian" wrote in message
...
Paul...dont look now, but that airplane is NOT flying off the ground
until the AIRSPEED is up...the treadmill is only moving the TIRES, that
means diddly squat to an airplane.

Damian, don't look now but Paul is exactly right (except for his rude
nature, of course).

The treadmill is irrelevant to the airplane's motion. If the airplane is
stationary on the treadmill, it's because it has a headwind the same speed
as the treadmill and enough thrust to fly into the headwind at the same
speed as the treadmill. Of course, the wheels will be turning on the
treadmill, but only because the treadmill is rotating them against the
air-based stationary nature of the airplane.

Without a suitable headwind for the airplane to fly into, the treadmill
would just push the airplane backward. Airplanes don't use their wheels
for transmitting power to forward motion (most don't, anyway ).

Pete

Actually, this has a real world parallel. A Seaplane taking off (or
landing) on a river. There are three speeds here. The speed relative to
the conveyer belt (river), the speed relative to the non-moving ground
(riverbank), and the airspeed. Put in some wind and you can get some
complicated scenarios.

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

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.

"Doug" wrote in 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.

Another way to say it; it had better be a long conveyer belt, cause the prop
is pulling the plane forward, without caring how fast the wheels are going.
That will make the necessary airspeed to lift off.
--
Jim in NC

experiment, go run with a kite(in a no wind situation) untill it flies,
measure the speed youre running. get on a teadmill and run that speed
that it took to make the kite fly. does the kite fly when youre on the
treadmill? no... same thing as the airplane on the conveyor belt. i
know i said i was done but i cant keep my hand out of this.
jester

There will be airspeed felt by the plane in the area of the propellor
wash. Out of the prop wash, since the plane is not moving relative to
the surrounding air, there will be no relative wind felt by the
airplane. The airplane MIGHT take off, but it will not be a normal
takeoff, at least not for a normal airplane with 36' wingspan and a 6'
propellor. I really don't think there is enough information to know the
answer for sure. Too many unknowns.

This is one of these "frame of reference" problems.

First I'm not a pilot.... But the engine is providing thrust, not driving
the wheels like a car. The airplane is gonna move regardless of what speed
the wheels are or are not turning. What the wheels do is only slightly
relevant if at all unless you're holding the brake....and even that wouldn't
matter if you're on a treadmill. Second.....are we talking about a
treadmill or a conveyer belt? The treadmill may or may not move at all
relative to the world if it's the "classic" kind ... (i.e. non-motorized).
Depends on whether the wheels or treadmill has better bearings.

"Morgans" wrote in message
...

"Doug" wrote in 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.

Another way to say it; it had better be a long conveyer belt, cause the
prop
is pulling the plane forward, without caring how fast the wheels are
going.
That will make the necessary airspeed to lift off.
--
Jim in NC

"Doug" wrote:

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.

Not at all complicated. The propulsion system is irrelevant. The given
fact is that the airplane's speed (not it's speed relative to the
conveyor) is equal to the conveyor's speed, but in the opposite
direction. When that speed is sufficient for flight, it will fly.
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.

The propulsion system is irrelevant as long as it is independant of the
treadmill.

--
-------------------------------
Travis
"alexy" wrote in message
...
"Doug" wrote:

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.

Not at all complicated. The propulsion system is irrelevant. The given
fact is that the airplane's speed (not it's speed relative to the
conveyor) is equal to the conveyor's speed, but in the opposite
direction. When that speed is sufficient for flight, it will fly.
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked
infrequently.