FYI: Dec 12 MythBusters: Airplane Hour

"B A R R Y" wrote

If it were so cut and dried, why does it generate threads of several
hundred messages here? G

Just goes to show that there are a LOT of stupid people out there, posting
on usenet.

But we knew that, with Anthony as their posterboy. :-(
--
Jim in NC

On Sun, 9 Dec 2007 09:12:27 -0400, wrote:

and if the belt is running so the the wheels of the
aircraft are spinning madly while it stays still then again you already know
the answer. What are they trying to prove?

I guess there are still a couple of people out there that believe the
aircraft won't take off.


--
Dallas

I see, is this "people" or pilots. Or those computer game pilots who have
all the hard earned knowledge of how flight is accomplished. (Sorry just got
lectured at length last week about how MY aircraft works, by a computer
flier.) (stupid effin git!)

Anyway, I'll likely miss the show. My guess is that I'm better off without
it.

"Dallas" wrote in message
...
On Sun, 9 Dec 2007 09:12:27 -0400, wrote:

and if the belt is running so the the wheels of the
aircraft are spinning madly while it stays still then again you already
know
the answer. What are they trying to prove?

I guess there are still a couple of people out there that believe the
aircraft won't take off.


--
Dallas

Dallas wrote:
On Sun, 9 Dec 2007 09:12:27 -0400, wrote:

and if the belt is running so the the wheels of the
aircraft are spinning madly while it stays still then again you
already know the answer. What are they trying to prove?

I guess there are still a couple of people out there that believe the
aircraft won't take off.


Add a pinch of gadfly and stir until frothy......... d:-)

"Some Other Guy" wrote in message
...
" Vacant lot wrote:
I don't understand the premise of the conveyor belt thing. If you are
talking about thrusting an aircraft forward, like a catapult, you already
know the answer, and if the belt is running so the the wheels of the
aircraft are spinning madly while it stays still then again you already
know the answer. What are they trying to prove? I've seen the show but I
watch very little tv, have they run out of urban myths?

A friend of mine was absolutely convinced that if you are flying into a
strong headwind close to stall speed and make a U-turn, you will stall
(because now the wind is coming "from behind").

The basics of flight just isn't obvious to some people.


Ah, but if you are flying near stall with the wind, and the wind suddenly
slows, will you stall?
..OR.
If you are slow on approach, into a gusty head wind, and a gust suddenly
resides, will you stall?

In article ,
"Maxwell" wrote:

"Some Other Guy" wrote in message
...
" Vacant lot wrote:
I don't understand the premise of the conveyor belt thing. If you are
talking about thrusting an aircraft forward, like a catapult, you already
know the answer, and if the belt is running so the the wheels of the
aircraft are spinning madly while it stays still then again you already
know the answer. What are they trying to prove? I've seen the show but I
watch very little tv, have they run out of urban myths?

A friend of mine was absolutely convinced that if you are flying into a
strong headwind close to stall speed and make a U-turn, you will stall
(because now the wind is coming "from behind").

The basics of flight just isn't obvious to some people.


Ah, but if you are flying near stall with the wind, and the wind suddenly
slows, will you stall?

Yes -- Your momentum needs to catch up with your new (reduced) airspeed.

.OR.
If you are slow on approach, into a gusty head wind, and a gust suddenly
resides, will you stall?

It depends on how much margin you have between stall and airspeed to
begin with. If the margin is less than the (now non-existent) gust, you
will stall. Otherwise, you will see a sudden increase in sink rate.

Ah, but if you are flying near stall with the wind, and the wind suddenly
slows, will you stall?

Yes -- Your momentum needs to catch up with your new (reduced) airspeed.

.OR.
If you are slow on approach, into a gusty head wind, and a gust suddenly
resides, will you stall?

It depends on how much margin you have between stall and airspeed to
begin with. If the margin is less than the (now non-existent) gust, you
will stall. Otherwise, you will see a sudden increase in sink rate. I
guess it might not be fair to call it a stall.

Everyone, remember that this is not a real airplane, but instead it is a
theoretical airplane, like in physics class, where they tell you to figure a
problem without any friction being taken into account.

This airplane was going 70 knots (airspeed) north, with a 30 knot wind out
of the north, and it suddenly, and instantly is going to be going south, in
..1 second.

That means it had 40 knots worth of momentum. When that sudden reversal of
direction takes place, it will have the same momentum, for that first
instant of reversed flight, until the wind blowing at its back starts to
blow on it and accelerate it. That means the 40 knots of momentum will have
the airspeed component of the tailwind subtracted from it, so 40 knots minus
30 knot wind means it will see an airspeed (only for an instant) of 10
knots, until the tail wind plus the thrust starts accelerating the plane
back to its original airspeed of 70 knots.

I would agree that the airplane would develop a VERY serious sink rate.
Would that be a stall, though? g
--
Jim in NC

On Dec 10, 12:58 am, "Morgans" wrote:
Ah, but if you are flying near stall with the wind, and the wind suddenly

slows, will you stall?

Yes -- Your momentum needs to catch up with your new (reduced) airspeed.

.OR.
If you are slow on approach, into a gusty head wind, and a gust suddenly
resides, will you stall?

It depends on how much margin you have between stall and airspeed to
begin with. If the margin is less than the (now non-existent) gust, you
will stall. Otherwise, you will see a sudden increase in sink rate. I
guess it might not be fair to call it a stall.

Everyone, remember that this is not a real airplane, but instead it is a
theoretical airplane, like in physics class, where they tell you to figure a
problem without any friction being taken into account.

This airplane was going 70 knots (airspeed) north, with a 30 knot wind out
of the north, and it suddenly, and instantly is going to be going south, in
.1 second.

That means it had 40 knots worth of momentum. When that sudden reversal of
direction takes place, it will have the same momentum, for that first
instant of reversed flight, until the wind blowing at its back starts to
blow on it and accelerate it. That means the 40 knots of momentum will have
the airspeed component of the tailwind subtracted from it, so 40 knots minus
30 knot wind means it will see an airspeed (only for an instant) of 10
knots, until the tail wind plus the thrust starts accelerating the plane
back to its original airspeed of 70 knots.

I would agree that the airplane would develop a VERY serious sink rate.
Would that be a stall, though? g
--
Jim in NC

I suspect it would pile in very shortly after the turn began. Making
a turn at "near stall speed" into a head wind to begin with....

Harry K

I think that a plane could be doing 70kts due north and be going south
..1 second later without missing a beat.

Morgans wrote:
Ah, but if you are flying near stall with the wind, and the wind suddenly
slows, will you stall?
Yes -- Your momentum needs to catch up with your new (reduced) airspeed.

.OR.
If you are slow on approach, into a gusty head wind, and a gust suddenly
resides, will you stall?
It depends on how much margin you have between stall and airspeed to
begin with. If the margin is less than the (now non-existent) gust, you
will stall. Otherwise, you will see a sudden increase in sink rate. I
guess it might not be fair to call it a stall.

Everyone, remember that this is not a real airplane, but instead it is a
theoretical airplane, like in physics class, where they tell you to figure a
problem without any friction being taken into account.

This airplane was going 70 knots (airspeed) north, with a 30 knot wind out
of the north, and it suddenly, and instantly is going to be going south, in
.1 second.

That means it had 40 knots worth of momentum. When that sudden reversal of
direction takes place, it will have the same momentum, for that first
instant of reversed flight, until the wind blowing at its back starts to
blow on it and accelerate it. That means the 40 knots of momentum will have
the airspeed component of the tailwind subtracted from it, so 40 knots minus
30 knot wind means it will see an airspeed (only for an instant) of 10
knots, until the tail wind plus the thrust starts accelerating the plane
back to its original airspeed of 70 knots.

I would agree that the airplane would develop a VERY serious sink rate.
Would that be a stall, though? g

"Some Other Guy" wrote

A friend of mine was absolutely convinced that if you are flying into a
strong headwind close to stall speed and make a U-turn, you will stall
(because now the wind is coming "from behind").

The basics of flight just isn't obvious to some people.

Partially so. IF you could do a 180 degree turn super fast, like .1
second, you would stall.

At least for the amount of time it takes the airplane to accelerate, the
wind would be making you go too slow.

Of course, no plane can make a 180 degree turn that fast, so we are all safe
from the dreaded downwind turn. g

I think one thing that people don't realize is that while a car can make an
instant turn, an airplane can not.

Well, all but Shawn Tucker's plane. I think he could make the turn in less
time than .1 second, from the crazy crap I have seen him do!
--
Jim in NC