New trainer from SZD Bielsko

Ian wrote:
What you're forgetting - or perhaps what nobody told you - is that
it's the motion of the centre of pressure which really matters.
Basically, as the AOA increases the net lift force on the wing appears
to move forwards, and as the AOA decreases it moves back.

Much as I may want to blame this on others, it's likely that I just forgot
about it, or never managed to think of it.

This is unstable, since - all other things being equal: nose up -
increased AOA - cop moves forwards - nose up moment - nose up. So
what you do is stick a tail on the back. Now nose up - positive AOA
on tail - lift at tail and, if you get the sums and moment arms
right, this balances the pitching moment caused by the cop moving
forwards.

Now it all makes so much more sense.

As you'll have guessed, this is an enthusiasm of mine. I think a lot
of people would fly better, and find it easier, if they understood the
physics better. I include instructors, I'm afraid - hardly any of them
know why you need back stick in a turn, for example.

I agree that the more you know the better off you are in this regard.
Thanks to you, I'm now better off than I was before!

--
Michael Ash
Rogue Amoeba Software

On Jul 2, 7:16 pm, Michael Ash wrote:
Ian wrote:
What you're forgetting - or perhaps what nobody told you - is that
it's the motion of the centre of pressure which really matters.
Basically, as the AOA increases the net lift force on the wing appears
to move forwards, and as the AOA decreases it moves back.

Much as I may want to blame this on others, it's likely that I just forgot
about it, or never managed to think of it.

This is unstable, since - all other things being equal: nose up -
increased AOA - cop moves forwards - nose up moment - nose up. So
what you do is stick a tail on the back. Now nose up - positive AOA
on tail - lift at tail and, if you get the sums and moment arms
right, this balances the pitching moment caused by the cop moving
forwards.

Now it all makes so much more sense.

As you'll have guessed, this is an enthusiasm of mine. I think a lot
of people would fly better, and find it easier, if they understood the
physics better. I include instructors, I'm afraid - hardly any of them
know why you need back stick in a turn, for example.

I agree that the more you know the better off you are in this regard.
Thanks to you, I'm now better off than I was before!

--
Michael Ash
Rogue Amoeba Software

O'K guys...what happen to the original thread about new sailplane? I
thought I posted a little info about the SZD 54-2 Perkoz and we ended
up where?

Jacek
Washington State

At 15:54 03 July 2007,
wrote:

O'K guys...what happen to the original thread about
new sailplane? I
thought I posted a little info about the SZD 54-2 Perkoz
and we ended
up where?

Jacek
Washington State

New SZD Perkoz

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V

Have they fixed peculiarities of Puchacz?

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Appropriateness of spinnable training gliders

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Stalling/spinning on winch launch

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overspeeding on winch lauch

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max winch launch speed limits

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definition and cause of Vne

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Lifting and drag forces on a glider

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more advanced aerodynamics

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confusion about the physics of how gliders fly.

Answer your question?!

O'K guys...what happen to the original thread about

New SZD Perkoz

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....
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confusion about the physics of how gliders fly.

You see, it always boils down to the essential question wheter it's more
appropriate to use Bernoulli or Newton to explain lift.

"Sandro Rodriguez" wrote in message
...

You see, it always boils down to the essential question weather it's more
appropriate to use Bernoulli or Newton to explain lift.

How about a compromise ... Bernewton?


Vaughn

On 3 Jul, 21:57, Sandro Rodriguez wrote:

You see, it always boils down to the essential question wheter it's more
appropriate to use Bernoulli or Newton to explain lift.

What do you mean "or"? Bernouilli comes straight out of Newtonian
physics!

Ian

On Jun 21, 10:49 am, Ray Lovinggood
wrote:
The 'new' SZD two place ship does look interesting,
but is it a better 'mid price range' trainer than the
PW6? What about thePeregrine(nee KR-02)? And, of
course, the tried and true Blaniks (L-13 and L-23).

Is thePeregrineeven alive these days?

Oh yea, how about that other new two seater, the Taunus.
That's a nice looking ship! Even available as a self-launcher,
I think.

Ray Lovinggood
Carrboro, North Carolina, USA

I'd left a message and e-mailed http://www.PeregrineAerospace.com the
other day. Patty Barry called today to update me on the status of
their project. Some of the delay is certifying material changes, so
that domestically available steel and aluminum can be used. This also
includes weldment processes and testing, so progress takes some time.
She was cautiously optimistic about this winter.

Frank Whiteley

On Jun 21, 11:11 pm, Frank Whiteley wrote:
Actually, I thought I read in some club NL that it was in Oregon.
Maybe they have one of the Nevada corporations that were being pitched
on the radio a couple of years ago;^)

Frank

Just following up with a new data point.

The original SZD-54 Perkoz is apparently based in Colorado Springs and
the owner has now flown it several times.

Frank Whiteley