Can a Plane on a Treadmill Take Off?

"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.

Only if there is an 80 mph tailwind.

If the plane is rolling 80mph against a conveyor going 80mph back the
difference would be zero.

-Robert

"Robert M. Gary" wrote:

Only if there is an 80 mph tailwind.

If the plane is rolling 80mph against a conveyor going 80mph back the
difference would be zero.

True. But I was referring to the problem stated, that the conveyor was
moving the same speed and opposite direction to the speed and
direction that the plane was MOVING, not this different scenario in
which the conveyor was moving the opposite direction and same speed to
that at which the plane's tires were turing.

--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.

Robert M. Gary wrote:
Only if there is an 80 mph tailwind.


If the plane is rolling 80mph against a conveyor going 80mph back the
difference would be zero.


BUT-what is the total friction force from the wheels? Certainly it's
less than the thrust from the engine--I mean, that's what wheels are
designed for, to have as little rolling friction as possible. So let's
add this up... forces acting on airplane are thrust, aerodynamic drag,
and an essentially negligible amount of drag from the wheels. Add it
up, and since the thrust is greater than the drag (as it would be on a
normal takeoff) the airplane accelerates. As I said in another post,
since wheels are designed for minimal friction, just pretend that they
are frictionless, and therefore not even there (anti-gravity airplane).
What is the conveyor belt going to push against now?

What is the conveyor belt going to push against now?

The conveyor belt is pushing against the force of the prop through the
air but we don't care. The problem stated that they are doing 80mph, we
shouldn't worry about how the plane is able to do 80mph on the belt.

-Robert