1-34 Rudder

[DGRTEK]

Serious question. I've spoken to several pilots regarding the handling
characteristics of the 1-34, and the general comment was that the Rudder could
have been a bit more effective.

My question is, Has anyone tried to modify the rudder to be more effective?
What would be the result of adding a small tab to the trailing edge of the
rudder? I'm not concerned with legality now, I'm curious to know if it could
be done. TIA

Douglas

[Shawn Curry]

DGRTEK wrote:
> Serious question. I've spoken to several pilots regarding the handling
> characteristics of the 1-34, and the general comment was that the Rudder could
> have been a bit more effective.
>
> My question is, Has anyone tried to modify the rudder to be more effective?
> What would be the result of adding a small tab to the trailing edge of the
> rudder? I'm not concerned with legality now, I'm curious to know if it could
> be done. TIA
>
> Douglas
>
>
Its been a while since I've flown a 1-34, but my recollection is it has
reasonable rudder effectiveness. Lots better than a Grob 103. Never
noticed, but does it run out of rudder when the stick is cranked all the
way over going into a tight thermal? Did those you talked to think it
should be modified?
I guess my thought is, if its only a problem a small part of the time,
why hassle with it?

Shawn

[Nolaminar]

Modification to an aircraft with an Standard Airworthiness? Probably not worth
the paperwork/engineering effort.
GA

[DGRTEK]

That's what everyone keeps telling me! I'm still curious though as to what it
would take to give it a bit more "rudder".

I have a simplistic view in my head of a small extension. I'm just wondering
what it would really take.

Douglas

[Steve Bralla]

(DGRTEK) writes:

>
>My question is, Has anyone tried to modify the rudder to be more effective?
>What would be the result of adding a small tab to the trailing edge of the
>rudder? I'm not concerned with legality now, I'm curious to know if it could
>be done. TIA
>
>Douglas

Is the gap between the fin and rudder sealed? Do that first.
Now there is a question, is it legal to install your own seals on a glider with
a Standard Cert?

Steve

[Shawn Curry]

DGRTEK wrote:

> That's what everyone keeps telling me! I'm still curious though as to what it
> would take to give it a bit more "rudder".
>
> I have a simplistic view in my head of a small extension. I'm just wondering
> what it would really take.
>
> Douglas
>
>
Hmm! OK, I always liked the one I flew fine like it was :-)
I agree with the crowd. The hassle (337? STC?) would be a big pain for
very little gain.

Shawn

[Jeremy Zawodny]

DGRTEK wrote:
> Serious question. I've spoken to several pilots regarding the handling
> characteristics of the 1-34, and the general comment was that the Rudder could
> have been a bit more effective.

I guess it depends what you compare it to. I've been pretty happy
flying our club's 1-34 (the few times I have). Compared to your Grob
103, it's really not a problem at all.

Jeremy

[Kirk Stant]

(DGRTEK) wrote in message >...
> Serious question. I've spoken to several pilots regarding the handling
> characteristics of the 1-34, and the general comment was that the Rudder could
> have been a bit more effective.
>
> My question is, Has anyone tried to modify the rudder to be more effective?
> What would be the result of adding a small tab to the trailing edge of the
> rudder? I'm not concerned with legality now, I'm curious to know if it could
> be done. TIA
>
> Douglas


The rudder is fine, don't worry about it!

Have you flown a 1-34 yet? It's not quite an LS4, but it's better
than a PW-5 - from personal experience out here in Arizona.

A bit stiff on the controls, but that might just be a need for some
lube...

Wash it, wax it, hose out the dirt from the fuselage, put a nice vario
in it, and go fly - it's a great first XC glider.

Kirk

[Roy Bourgeois]

Doug:

Actually - your observation is quite perceptive. The 1-34 IS a bit
under-ruddered. However, the problem is not it's size but rather the
fuselage length and the distance of the rudder from the center of the yaw
axis. The 1-34 original design concept was to be a "metalized" Slingsby
Dart - with optional 15 or 17m wings. Schweizer only made 1 set of 17
meter wings (nobody wanted them) but they made the fuselage much longer
than necessary for a 15m ship. Compare the fuselage length between the
1-34 and the 1-35 - both are 15m gliders but there is something like a 40"
difference between center of yaw axis and the rudder hinge line. So - you
would have to make the rudder much, much, bigger on the 1-34 to have a
significant effect (and that creates a weight and balance problem because
the weight is so far back).

This is why the big open class gliders like the Nimbus 3 have spoilers on
the wing tips to help the rudder. Because of the fuselage length needed
for the long wings - you can't make a rudder big enough.

Roy B.

[Eric Greenwell]

Roy Bourgeois wrote:
> Doug:
>
> Actually - your observation is quite perceptive. The 1-34 IS a bit
> under-ruddered. However, the problem is not it's size but rather the
> fuselage length and the distance of the rudder from the center of the yaw
> axis. The 1-34 original design concept was to be a "metalized" Slingsby
> Dart - with optional 15 or 17m wings. Schweizer only made 1 set of 17
> meter wings (nobody wanted them) but they made the fuselage much longer
> than necessary for a 15m ship. Compare the fuselage length between the
> 1-34 and the 1-35 - both are 15m gliders but there is something like a 40"
> difference between center of yaw axis and the rudder hinge line. So - you
> would have to make the rudder much, much, bigger on the 1-34 to have a
> significant effect (and that creates a weight and balance problem because
> the weight is so far back).
>
> This is why the big open class gliders like the Nimbus 3 have spoilers on
> the wing tips to help the rudder. Because of the fuselage length needed
> for the long wings - you can't make a rudder big enough.

I'm confused: are you saying the 1-34 has a weak rudder because the
fuselage is too long? If you are, could you explain how extra length is
a problem, because normally that increases tail effectiveness.

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Eric Greenwell
Washington State
USA

[Roy Bourgeois]

That's right Eric - Think of the fuselage/rudder as a lever moving the
glider about the center of the yaw axis. The farther away the rudder is
from the center of that axis the farther it must move to have the correct
effect. Only by increasing the size can we make it move laterally far and
fast (but that creates a weight problem). A longer fuselage reduces the
"force" needed - but the tail it needs to travel laterally farther faster
to have the appropriate effect. Thus, the 1-34 is very stable in yaw - but
it really doesn't have adequate yaw response when you step on the
rudder. Consider for a minute the size of the rudder on the Genisis
2: It's downright tiny (maybe 25% the size of the 1-34's) - but it is so
close to the center of yaw axis that it is more than adequate - and much,
much, more responsive than the 1-34. In general, the farther the rudder
hinge line is from the wing spar - the bigger the rudder needs to be for
proper yaw response.

Roy

[Eric Greenwell]

Roy Bourgeois wrote:
> That's right Eric - Think of the fuselage/rudder as a lever moving the
> glider about the center of the yaw axis. The farther away the rudder is
> from the center of that axis the farther it must move to have the correct
> effect.

Being further back puts it in a slightly different airstream, giving it
a slightly lower angle of attack (less than 2 degrees, even in a tight
circle) compared to one half as far from the wing. Since it has twice
the lever arm, it only needs half the lift of the closer one to counter
the adverse yaw, so losing two degree in AOA isn't a problem; in fact,
it's probably a help because so much less force is needed.

Only by increasing the size can we make it move laterally far and
> fast (but that creates a weight problem). A longer fuselage reduces the
> "force" needed - but the tail it needs to travel laterally farther faster
> to have the appropriate effect. Thus, the 1-34 is very stable in yaw - but
> it really doesn't have adequate yaw response when you step on the
> rudder. Consider for a minute the size of the rudder on the Genisis
> 2: It's downright tiny (maybe 25% the size of the 1-34's) - but it is so
> close to the center of yaw axis that it is more than adequate - and much,
> much, more responsive than the 1-34.

I think the Genesis is a poor comparison, because it's reflexed airfoil
creates less adverse yaw in the first place. My flapped glider acts the
same way at any given speed: positive flap requires more rudder in a
turn than when negative flap is used. Another reason: the rudder is
actually further from the wing that it appears, because of the sweep
forward. You can't measure to the wing root to get a meaningful
distance, and you need to account for the sweep backward in the rudder.
These factors put the rudder farther from the wing than you might guess
from looking a side view drawing.

The 1-34 poor rudder response may due things I can only guess at:
perhaps the fin/rudder airfoil is poor (note how old gliders tend to
have very wide rudders compared to newer gliders); perhaps it has a
differential aileron deflection that is poor; perhaps the airfoil at the
aileron is high drag with down aileron. I'm really skeptical that
shortening the tail boom would help matters!

In general, the farther the rudder
> hinge line is from the wing spar - the bigger the rudder needs to be for
> proper yaw response.

If this were true, why do gliders have such long tail booms? Why aren't
they all as short as the Genesis? If being closer meant smaller
surfaces, we'd see all gliders with the surfaces mounted close to the
wing. I'm also skeptical that this idea has been missed by best glider
designers in the world.

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Eric Greenwell
Washington State
USA

[AZSKYBUM]

I flew my 1-34R for three years and found that taping the rudder hinge on both
the inside and outside of the hinged side does very little to improve
efectiveness, unlike the ailerons where it helps alot. Make sure the fabric is
secured to the rudder and isn't loose, some people don't ribstich them. I now
have a SGS 1-23 and it has a little, ineffective rudder compared to the
1-34.Enjoy your ship its a great glider just heavy to assemble.
Curtis Clark
Scottsdale, Arizona

[Roy Bourgeois]

Eric:

I think we are really saying the same thing - just focusing on different
effects. If you pick up the tail of a long fuselage glider and rotate it
around it's wheel 360 degrees on the ground, it will take you longer than
when you do the same with a short fuselage glider - because the radius of
the circle you must walk is different (and you need more steps with the
long fuselage glider). Or, you could change the speed of your walk (which
is what changing the rudder size does). This is why the 1-34 seems slow in
rudder response. It is about the longest fuselage ever put on a 15m ship.
Now, there are many other reasons why a designer may want a long fuselage
(particularly stability) - but the reasons selected by the 1-34's designers
(I pass on whether they were the "best in the world") were not particularly
good ones, and once they abandoned the idea of the 17m wing they should
have shortened the fuselage (as they did with the later 1-35 and 1-36).

[Eric Greenwell]

Roy Bourgeois wrote:
> Eric:
>
> I think we are really saying the same thing - just focusing on different
> effects.

I'm pretty sure you are saying shorter arm, smaller rudder, and I'm
saying shorter arm, bigger rudder!

If you pick up the tail of a long fuselage glider and rotate it
> around it's wheel 360 degrees on the ground, it will take you longer than
> when you do the same with a short fuselage glider - because the radius of
> the circle you must walk is different (and you need more steps with the
> long fuselage glider). Or, you could change the speed of your walk (which
> is what changing the rudder size does).

This is not a good analogy: in a steady turn, all the pieces of the
glider rotate at the same rate (revolutions per minute). Some of the
pieces are moving _faster_ (knots) than other pieces, especially the
inner and outer wing tips. That's why it doesn't take longer to "walk
the tail of the glider around" - you walk faster if you are farther from
the center of the circle. On a percentage basis, you aren't much
farther: perhaps a foot or two out of 150 feet or so.

But it isn't in the steady turn that the 1-34 has a problem, it's during
the entry to the turn.

This is why the 1-34 seems slow in
> rudder response.

I've never flown one, but I'm pretty sure it isn't _slow_ in rudder
response, it just doesn't have enough rudder force to counteract the
adverse yaw from the ailerons when they are applied to turn.

Unless I've really missed something (it happens!), the "under ruddered"
comment only applies to the transient turn entry phase. In other words:
full aileron, full rudder, but the nose moves opposite the turn. This
isn't related to the speed at which the tail moves around, because
initially, the tail movement is in the wrong direction. As it settles
into the turn, the ailerons are moved opposite the turn until you have
some "top aileron", the amount of rudder is reduced, and everything is OK.

It is about the longest fuselage ever put on a 15m ship.
> Now, there are many other reasons why a designer may want a long fuselage
> (particularly stability) - but the reasons selected by the 1-34's designers
> (I pass on whether they were the "best in the world") were not particularly
> good ones, and once they abandoned the idea of the 17m wing they should
> have shortened the fuselage (as they did with the later 1-35 and 1-36).

I still don't understand how rudder power is improved by shortening the
tail boom, andI still don't understand why the best sailplane designers
in the world haven't seized on the idea of making the tail surfaces
smaller AND making the boom shorter.

This comment addresses the orginal poster's question about "improving"
the rudder: Wil Schuemann told me the way to avoid this problem is by
using less aileron, not by making a bigger rudder. Less aileron, less
drag from the ailerons (drag is what the rudder is compensating for);
less drag = good. Not as pleasant to fly, but more efficient.
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Eric Greenwell
Washington State
USA

[Bert Willing]

The effect of any control surface is the product of lever x surface.
Longer fuselage (lever) makes up for smaller rudder. Your line of thought
does not work.

--
Bert Willing

ASW20 "TW"


"Roy Bourgeois" > a écrit dans le message de
...
> That's right Eric - Think of the fuselage/rudder as a lever moving the
> glider about the center of the yaw axis. The farther away the rudder is
> from the center of that axis the farther it must move to have the correct
> effect. Only by increasing the size can we make it move laterally far and
> fast (but that creates a weight problem). A longer fuselage reduces the
> "force" needed - but the tail it needs to travel laterally farther faster
> to have the appropriate effect. Thus, the 1-34 is very stable in yaw - but
> it really doesn't have adequate yaw response when you step on the
> rudder. Consider for a minute the size of the rudder on the Genisis
> 2: It's downright tiny (maybe 25% the size of the 1-34's) - but it is so
> close to the center of yaw axis that it is more than adequate - and much,
> much, more responsive than the 1-34. In general, the farther the rudder
> hinge line is from the wing spar - the bigger the rudder needs to be for
> proper yaw response.
>
> Roy
>
>
>
>
>

[Doug Hoffman]

Bert Willing wrote:

> The effect of any control surface is the product of lever x surface.
> Longer fuselage (lever) makes up for smaller rudder. Your line of thought
> does not work.

Aren't these actually competing effects? Certainly the longer fuse will
have an increased polar moment of inertia about the yaw axis. Also, the
longer fuse *will* present more air-drag resistance to yaw movement, and the
tail will have to be dragged through more air for the same yaw rotation.
Then of course the rudder has more "mechanical advantage" due to the longer
lever arm as you point out.

I think both lines of thought are basically correct. The question is
quantifying one effect vs. the other, I believe. Interesting discussion.

Regards,

-Doug

[Michael McNulty]

"Roy Bourgeois" > wrote in message
...
> Eric:
>
> I think we are really saying the same thing - just focusing on different
> effects. If you pick up the tail of a long fuselage glider and rotate it
> around it's wheel 360 degrees on the ground, it will take you longer than
> when you do the same with a short fuselage glider - because the radius of
> the circle you must walk is different (and you need more steps with the
> long fuselage glider). Or, you could change the speed of your walk (which
> is what changing the rudder size does). This is why the 1-34 seems slow
in
> rudder response. It is about the longest fuselage ever put on a 15m ship.
> Now, there are many other reasons why a designer may want a long fuselage
> (particularly stability) - but the reasons selected by the 1-34's
designers
> (I pass on whether they were the "best in the world") were not
particularly
> good ones, and once they abandoned the idea of the 17m wing they should
> have shortened the fuselage (as they did with the later 1-35 and 1-36).
>
>
>

Your theory goes against every thing I've ever seen in aircraft stabilty and
control text books. The effectiveness the the tail surfaces for stabilty
and control is measured by the "tail volume coefficient", which depends on
the product of the tail area and it's moment arm (tail length). More is
better for stability and control. The reason some aircraft have big
vertical tails and long tail booms is that they need alot of tail
effectiveness; one is not fighting the other. The idea that a long tail
boom lessens lateral-directional stability or control is silly.

[Roy Bourgeois]

I think that the difference is that my original post focused on "rudder
response" and others are focusing on "yaw stability" - which are different
and somewhat opposite. The 1-34 is quite stabile in yaw but as Doug noted
in his first post, it's response (time to desired effect) to your stepping
on the pedal is pretty bad. I flew several 1-34s about 250 hours (and
still occasionally). It doesn't have a problem with adverse yaw in a
turn. But when you step on the pedal (say, to begin a slip) - nothing much
happens (compared to other gliders). I was suggesting to Doug (and still
believe) that the lack of rudder "response" is a function of the
extraordinary fuselage length and that he would need a much bigger rudder
to solve that problem.

Now - if somebody will show me how to make my Nimbus 3 do ANYTHING
responsively - I'll be eternally grateful

Roy

[Bert Willing]

And you're still wrong.
Michael is completely right that the control surface volume is the design
parameter for a the control surface (apart the airfoil of course).
Yaw stability and responsivity both depend on the rudder volume, but yaw
stability is achieved with less rudder volume than reponsitivity - so the
latter is basically a design tradeoff between responsitivity and drag.
Now if you don't believe that, get a textbook.

--
Bert Willing

ASW20 "TW"


"Roy Bourgeois" > a écrit dans le message de
...
> I think that the difference is that my original post focused on "rudder
> response" and others are focusing on "yaw stability" - which are different
> and somewhat opposite. The 1-34 is quite stabile in yaw but as Doug noted
> in his first post, it's response (time to desired effect) to your stepping
> on the pedal is pretty bad. I flew several 1-34s about 250 hours (and
> still occasionally). It doesn't have a problem with adverse yaw in a
> turn. But when you step on the pedal (say, to begin a slip) - nothing
much
> happens (compared to other gliders). I was suggesting to Doug (and still
> believe) that the lack of rudder "response" is a function of the
> extraordinary fuselage length and that he would need a much bigger rudder
> to solve that problem.
>
> Now - if somebody will show me how to make my Nimbus 3 do ANYTHING
> responsively - I'll be eternally grateful
>
> Roy
>
>
>
>
>

[Eric Greenwell]

Roy Bourgeois wrote:
> I think that the difference is that my original post focused on "rudder
> response" and others are focusing on "yaw stability" - which are different
> and somewhat opposite. The 1-34 is quite stabile in yaw but as Doug noted
> in his first post, it's response (time to desired effect) to your stepping
> on the pedal is pretty bad.

It sounds like you are saying it has plenty of rudder power, but the
response is slow. So...

If you are flying straight and level, then step on the rudder (no
ailerons), are you saying it is slower to yaw than most/many gliders
(i.e., slow response time)? But if you are patient (wait 2-3 seconds
more than you do in most/many gliders) it will have plenty of yaw (i.e.,
plenty of power)?

> I flew several 1-34s about 250 hours (and
> still occasionally). It doesn't have a problem with adverse yaw in a
> turn.

No glider has problem with adverse yaw once it's settled in a turn,
because very little aileron is required to hold a turn. It's always
during the turn entry/exit that adverse yaw is a problem.

But when you step on the pedal (say, to begin a slip) - nothing much
> happens (compared to other gliders). I was suggesting to Doug (and still
> believe) that the lack of rudder "response" is a function of the
> extraordinary fuselage length and that he would need a much bigger rudder
> to solve that problem.

The kind of response you need when entering a turn is force to
counteract the adverse yaw, not a rapid change in direction. During the
initial turn entry, the fuselage mainly rolls, not yaws.

Your concern about the length of the fuselage would be appropriate for
aerobatic maneuvers that involve rapid yawing, which is why aerobatic
aircraft typically are small. A Pitts is a good example of this. Short
wings and tails reduce the moment of inertia and the changes in angle of
attack due to motion about the axes, allowing rapid response. A glider
turn entry isn't rapid in yaw, so these effects aren't important, but
rudder force is, and a long boom makes it more effective.
>
> Now - if somebody will show me how to make my Nimbus 3 do ANYTHING
> responsively - I'll be eternally grateful

Can't help you there, but at the convention, it was interesting
listening to Dick Butler talk about cutting off the tail of his ASW 22
so he could graft on a longer boom and a new fin (and maybe new rudder -
I'm not sure about that) to improve the handling with the longer wing
tips he also installed. JJ might be able to help you, as a long time
Nimbus 3 owner, and I think he also has replaced a tail or two on them.
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Eric Greenwell
Washington State
USA

[Dave Nadler YO]

Roy - beg to differ - the 1-34 has inadequate yaw stability.
If you hold neutral rudder at moderate cruise speed in any
turbulence, it often does a very notable cha-cha in yaw.
Not as bad as some V-tail Bonanzas, but to me uncomfortable.
OK, find cha-cha in your textbooks...
Best Regards, Dave

Roy Bourgeois > wrote in message >...
> I think that the difference is that my original post focused on "rudder
> response" and others are focusing on "yaw stability" - which are different
> and somewhat opposite. The 1-34 is quite stabile in yaw but as Doug noted
> in his first post, it's response (time to desired effect) to your stepping
> on the pedal is pretty bad. I flew several 1-34s about 250 hours (and
> still occasionally). It doesn't have a problem with adverse yaw in a
> turn. But when you step on the pedal (say, to begin a slip) - nothing much
> happens (compared to other gliders). I was suggesting to Doug (and still
> believe) that the lack of rudder "response" is a function of the
> extraordinary fuselage length and that he would need a much bigger rudder
> to solve that problem.
>
> Now - if somebody will show me how to make my Nimbus 3 do ANYTHING
> responsively - I'll be eternally grateful
>
> Roy

[Andy Blackburn]

This is a pretty amusing conversation from an engineering
point of view - lots of opinions and a smattering of
facts - some of them even true!

Vertical tail volume is in fact the appropriate design
paramerter for determining static directional stability
for any aircraft. A longer moment arm and/or a larger
surface area (fin plus rudder) will increase stability.
Gliders have long tail booms because you get a better
drag tradeoff by making the boom longer than by making
the fin bigger. In addition, gilders generally need
more tail volume because their high aspect ratios generate
considerable adverse yaw. I have not looked at the
Genesis planform in detail, but I suspect (as has been
already observed) that it has a longer tail arm than
at first appears because of the forward sweep and wide
root chord. Even so, that vertical stab looks pretty
puny so I'd be curious to hear if it has the 'cha-chas'.

In terms of yaw authority (responsiveness), the size
of the rudder relative to the tail volume and yawing
inertia of the aircraft is the relevant attribute to
consider (airfoil matters too). By deflecting the rudder
you generate a sideways lift vector that creates a
yawing moment proportional to the tail arm. This moment
has to overcome the yawing inertia of the aircraft
to yield a yaw rate. The yaw rate (plus any dihedral)
will pickup the outside wing, which is why you often
lead a bit with rudder when initiating a turn, or to
pick up the inside wing when recovering from a turning
stall.

I flew a 1-34 for a few years before transitioning
to glass long ago. I don't particularly remember it
being underdamped in yaw, but I do remember it being
slow to enter a turn. I suspect the issue is that
it has a relatively small rudder and a lot of yaw inertia
(those wings are HEAVY). I also remember the ailerons
being quite stiff. I built up good biceps by the end
of the season.



At 19:48 15 February 2004, Dave Nadler Yo wrote:
>Roy - beg to differ - the 1-34 has inadequate yaw stability.
>If you hold neutral rudder at moderate cruise speed
>in any
>turbulence, it often does a very notable cha-cha in
>yaw.
>Not as bad as some V-tail Bonanzas, but to me uncomfortable.
>OK, find cha-cha in your textbooks...
>Best Regards, Dave
>
>Roy Bourgeois wrote in message news:...
>> I think that the difference is that my original post
>>focused on 'rudder
>> response' and others are focusing on 'yaw stability'
>>- which are different
>> and somewhat opposite. The 1-34 is quite stabile
>>in yaw but as Doug noted
>> in his first post, it's response (time to desired
>>effect) to your stepping
>> on the pedal is pretty bad. I flew several 1-34s
>>about 250 hours (and
>> still occasionally). It doesn't have a problem with
>>adverse yaw in a
>> turn. But when you step on the pedal (say, to begin
>>a slip) - nothing much
>> happens (compared to other gliders). I was suggesting
>>to Doug (and still
>> believe) that the lack of rudder 'response' is a function
>>of the
>> extraordinary fuselage length and that he would need
>>a much bigger rudder
>> to solve that problem.
>>
>> Now - if somebody will show me how to make my Nimbus
>>3 do ANYTHING
>> responsively - I'll be eternally grateful
>>
>> Roy
>

[Bill Daniels]

"Andy Blackburn" > wrote in message
...
> This is a pretty amusing conversation from an engineering
> point of view - lots of opinions and a smattering of
> facts - some of them even true!
>
> Vertical tail volume is in fact the appropriate design
> paramerter for determining static directional stability
> for any aircraft. A longer moment arm and/or a larger
> surface area (fin plus rudder) will increase stability.
> Gliders have long tail booms because you get a better
> drag tradeoff by making the boom longer than by making
> the fin bigger. In addition, gilders generally need
> more tail volume because their high aspect ratios generate
> considerable adverse yaw. I have not looked at the
> Genesis planform in detail, but I suspect (as has been
> already observed) that it has a longer tail arm than
> at first appears because of the forward sweep and wide
> root chord. Even so, that vertical stab looks pretty
> puny so I'd be curious to hear if it has the 'cha-chas'.
>

It doesn't.

Bill Daniels