Here are two simple questions. The glider is an ASK-21
and for both questions the wind conditions are a smooth
steady 25 knots with no wind shear or gradient.

1. The pilot is holding North on his compass and the
glider is trimmed for 43 knots. He has a 90 degree
right cross wind from the East. The pilot then releases
the controls to see what the glider will do.
Do you believe the glider will turn into the wind,
downwind or stay facing North?

2. The pilot next decides to practice stalls upwind and
downwind to find out if they are the same other than
the groundspeed.
Will he or should he notice any difference?

M Eiler

I'll bite

1 - stays facing north

2 - no difference

Ian

Martin Eiler wrote:

> Here are two simple questions. The glider is an ASK-21
> and for both questions the wind conditions are a smooth
> steady 25 knots with no wind shear or gradient.
>
> 1. The pilot is holding North on his compass and the
> glider is trimmed for 43 knots. He has a 90 degree
> right cross wind from the East. The pilot then releases
> the controls to see what the glider will do.
> Do you believe the glider will turn into the wind,
> downwind or stay facing North?

Ah geez. Is this a troll? I'll bite.
The glider will maintain its nnw ground track with the yaw string
straight back. duh!
>
> 2. The pilot next decides to practice stalls upwind and
> downwind to find out if they are the same other than
> the groundspeed.
> Will he or should he notice any difference?

Depends. Is the sun out or is it overcast? Serious(er) his ground
speed is different heading east and west. This would be noticeable if
he looks for it. More noticeable at lower altitudes.

Talk to your instructor more about this subject. Its important to your
safety that you have a good understanding. Usenet is not the best place
to learn about wind speed, relative wind, shear etc. "Stick and
Rudder" by Lanngewieche would be a good resource, as would Tom Knauff's
books. (Unless Tom wants to reply directly but that doesn't sell books ;-)

Shawn

LOL.. Martin... trying to gather data points for explaining someone's debate
with you?

Rule #1, Listen to Martin..
Rule #2, if in doubt.. Refer to Rule #1

heading of aircraft should not change.. ground track will remain the same

if the instance of stalls.. should not matter.. just depends on how fast he
either gets blown away from or back towards the airport during the stalls..

The aircraft.. once in the "air mass" does not care what a steady state air
mass motion is doing, only the pilot cares about what he needs to do in that
air mass to get to where the pilot wants to go.

BT

"Martin Eiler" > wrote in message
...
> Here are two simple questions. The glider is an ASK-21
> and for both questions the wind conditions are a smooth
> steady 25 knots with no wind shear or gradient.
>
> 1. The pilot is holding North on his compass and the
> glider is trimmed for 43 knots. He has a 90 degree
> right cross wind from the East. The pilot then releases
> the controls to see what the glider will do.
> Do you believe the glider will turn into the wind,
> downwind or stay facing North?
>
> 2. The pilot next decides to practice stalls upwind and
> downwind to find out if they are the same other than
> the groundspeed.
> Will he or should he notice any difference?
>
> M Eiler
>
>
>
>
>
>
>

Shawn,

Marty is not asking because he doesn't know the answer - he's a
Designated Pilot Examiner. I think he's just trying to stimulate some
discussion here and to get pilots to think about their airmanship.

SP AM

Shawn Curry > wrote in message
snip
> Talk to your instructor more about this subject. Its important to your
> safety that you have a good understanding. Usenet is not the best place
> to learn about wind speed, relative wind, shear etc. "Stick and
> Rudder" by Lanngewieche would be a good resource, as would Tom Knauff's
> books. (Unless Tom wants to reply directly but that doesn't sell books ;-)
>
> Shawn

Martin Eiler wrote:
> ...
> 2. The pilot next decides to practice stalls upwind and
> downwind to find out if they are the same other than
> the groundspeed.
> Will he or should he notice any difference?

If this is done sufficiently low, the wind gradient may
make some difference, but then there is a little chance
that the pilot may make the experience in the both
directions.

Steve Pawling wrote:

> Shawn,
>
> Marty is not asking because he doesn't know the answer - he's a
> Designated Pilot Examiner. I think he's just trying to stimulate some
> discussion here and to get pilots to think about their airmanship.
>
> SP AM
>

Oh. Nevermind

Shawn Curry wrote:

> Steve Pawling wrote:
>
>> Shawn,
>>
>> Marty is not asking because he doesn't know the answer - he's a
>> Designated Pilot Examiner. I think he's just trying to stimulate some
>> discussion here and to get pilots to think about their airmanship.
>>
>> SP AM
>>
>
> Oh. Nevermind

Well not quite. There was another post on a current thread, where the
poster wasn't clear on what happens when you turn 180 deg in a 15 kt
wind. I'm all for quizes, but Marty should note them as such.

Shawn

You'd be surprised how many pilots think the wind affects the glider's
controlability and stall characteristics. The closer it gets to the
ground, the more certain they become that the wind exerts a palpable
force on the glider. But I doubt any will voice such a belief in this
forum. Debrief them after flying in a stiff wind, and you might be
surprised (or not) by their comments.



"Martin Eiler" > wrote in message >...
> Here are two simple questions. The glider is an ASK-21
> and for both questions the wind conditions are a smooth
> steady 25 knots with no wind shear or gradient.
>
> 1. The pilot is holding North on his compass and the
> glider is trimmed for 43 knots. He has a 90 degree
> right cross wind from the East. The pilot then releases
> the controls to see what the glider will do.
> Do you believe the glider will turn into the wind,
> downwind or stay facing North?
>
> 2. The pilot next decides to practice stalls upwind and
> downwind to find out if they are the same other than
> the groundspeed.
> Will he or should he notice any difference?
>
> M Eiler

"Martin Eiler" > wrote in message >...
> Here are two simple questions. The glider is an ASK-21
> and for both questions the wind conditions are a smooth
> steady 25 knots with no wind shear or gradient.
>
> 1. The pilot is holding North on his compass and the
> glider is trimmed for 43 knots. He has a 90 degree
> right cross wind from the East. The pilot then releases
> the controls to see what the glider will do.
> Do you believe the glider will turn into the wind,
> downwind or stay facing North?
>
> 2. The pilot next decides to practice stalls upwind and
> downwind to find out if they are the same other than
> the groundspeed.
> Will he or should he notice any difference?
>
> M Eiler

I think number 1 depends on the yaw-stability of the sailplane. With
a great deal of positive stability, the vertical stabilizer will swing
the nose of the aircraft into the wind. I am only a student pilot and
I have never flown the ASK21. But, I know this happens with a trimmed
out free-flight model glider, so I assume once the pilot releases the
controls, the aircraft will behave as it is designed to do. With
negative or neutral yaw-stability, no change in direction should
result.

Number 2, well, it should not make a difference. The plane should be
moving with the airmass in this case, and the stall should behave as
normal. Only relative gound-speed would be different.

Best of luck getting a good variety of opinions,
Terrill