Two conveyor belt scenarios

An airplane lands on a conveyor belt that's moving at a constant speed
of Vref

(a) in the direction of the airplane's landing
(b) in the opposite direction of the airplane's landing

What do you suppose will happen? (b) will be rather more dicey than
(a), methinks. Presume a healthy long runway for the moment...

Ramapriya

wrote in news:1159120091.823667.280400
@m7g2000cwm.googlegroups.com:

An airplane lands on a conveyor belt that's moving at a constant speed
of Vref

(a) in the direction of the airplane's landing
(b) in the opposite direction of the airplane's landing

What do you suppose will happen? (b) will be rather more dicey than
(a), methinks. Presume a healthy long runway for the moment...

Ramapriya

Is this a powered conveyor or a gravity feed conveyor?

Rollers, Mattop, or Belt?

wrote in message
ups.com...
An airplane lands on a conveyor belt that's moving at a constant speed
of Vref

(a) in the direction of the airplane's landing
(b) in the opposite direction of the airplane's landing

What do you suppose will happen? (b) will be rather more dicey than
(a), methinks. Presume a healthy long runway for the moment...

We had this thread already. Looks like r.a.student had it already too. See
Google Groups.

Bottom line: since an airplane doesn't rely on the wheels for propulsion,
conveyor belts have nothing to do with whether an airplane can land or
takeoff, regardless of whether that conveyor belt is moving or not moving,
forward or backward.

During takeoff, there are no real secondary issues. During landing, braking
may be an issue, but at that point the question has nothing to do with
airplanes.

Pete

Peter Duniho wrote:
wrote in message
ups.com...
An airplane lands on a conveyor belt that's moving at a constant speed
of Vref

(a) in the direction of the airplane's landing
(b) in the opposite direction of the airplane's landing

What do you suppose will happen? (b) will be rather more dicey than
(a), methinks. Presume a healthy long runway for the moment...

We had this thread already. Looks like r.a.student had it already too. See
Google Groups.

Bottom line: since an airplane doesn't rely on the wheels for propulsion,
conveyor belts have nothing to do with whether an airplane can land or
takeoff, regardless of whether that conveyor belt is moving or not moving,
forward or backward.


Takeoff is clear, Pete. But I doubt landing would be that cut-and-dry.
Remember I said the conveyor is moving at a *constant* Vref. I'm sure
that'd cause problems once the plane loses aerodynamic braking and has
to rely on ground braking.

Not sure, of course - which is why I asked you guys

Ramapriya

I'm sure
that'd cause problems once the plane loses aerodynamic braking and has
to rely on ground braking.

You never said what you wanted the plane to do. First, the plane will
alight onto the conveyor belt. The tires will (or will not need to)
spin up.

Now what? That depends on what the pilot does, which depends on what
the pilot wants to accomplish. You didn't state that.

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

wrote in message
oups.com...
Takeoff is clear, Pete. But I doubt landing would be that cut-and-dry.

It is.

Remember I said the conveyor is moving at a *constant* Vref. I'm sure
that'd cause problems once the plane loses aerodynamic braking and has
to rely on ground braking.

You said nothing about braking, nor made any stipulation about braking
performance. If you have further facets to the question you'd like to
explore, feel free to post those. But as the question was stated, my answer
is accurate (as is Jose's).

And for the record, if you're concerned about issues with braking, why
aren't you concerned about issues during takeoff (in which the airplane is
theoretically stopped on the conveyor belt to start with)?

There is nothing aerodynamically interesting about the question. The only
interesting parts happen with respect to the wheel/belt interface, which is
the same whether you are talking about a plane, car, or whatever.

Pete

(a) in the direction of the airplane's landing

The airplane will touch down, and the tires will not spin.

(b) in the opposite direction of the airplane's landing

The airplane will touch down as before, and the tires will spin twice as
fast as they would have landing on still ground.

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

wrote in message
ups.com...
An airplane lands on a conveyor belt that's moving at a constant speed
of Vref

(a) in the direction of the airplane's landing
(b) in the opposite direction of the airplane's landing

What do you suppose will happen? (b) will be rather more dicey than
(a), methinks. Presume a healthy long runway for the moment...

Ramapriya


Oh Gawd, not again!

"Allen" wrote in message
...
Oh Gawd, not again!

Yeah, you would think that the ****in' trolls could at least make the effort
to be a bit more original...

Grumman-581 wrote:
"Allen" wrote in message
...
Oh Gawd, not again!

Yeah, you would think that the ****in' trolls could at least make the effort to be a bit more original...


I did read the conveyor belt thread (of Aug 04?) on takeoff, which made
me ask about this landing scenario (don't remember seeing one similar).


And find out what a troll means before using the word, Grumman.

Ramapriya