Fin Mounted TE Prob vs fuselage mounted TE prob

[[email protected]]

I have not received my soaring magazine yet this month but I hear there
is an article dealing with fin mounted vs fuselage mounted TE probes.

Anyone have thoughts on this issue?

Richard
www.craggyaero.com

[Bill Daniels]

> wrote in message
oups.com...
> I have not received my soaring magazine yet this month but I hear there
> is an article dealing with fin mounted vs fuselage mounted TE probes.
>
> Anyone have thoughts on this issue?
>
> Richard
> www.craggyaero.com
>

I read Dick's article with interest. He did his usual incredibly through
experimental work to support the probe design.

I see several advantages to the Johnson probe.

1. It's likely to be less sensitive to yaw with its single hole aft.
2. Shorter tubing runs that can be easily inspected and replaced if needed.
3. It eliminates the danger of breaking the fin mounted probe while
installing/removing the tail dolly.
4. Possibly faster and more accurate vario response since acceleration and
line capacity errors are reduced.
5, One less part to install (or forget)

Bill Daniels

[Ray Lovinggood]

One additional practical advantage to the fuselage
mounted TE:

If you forget to remove the TE probe from the fin-mounted
position and close the Cobra/Komet top with the glider
inside the trailer, you'll end up with another bend
in the TE probe.

That won't happen with a fuselage-mounted TE probe.

(Since I have a funky tube trailer, that isn't possible
with my ship. So, it didn't happen to me.)

Ray Lovinggood
Carrboro, North Carolina, USA

At 13:30 02 June 2005, Bill Daniels wrote:
>
> wrote in message
oups.com...
>> I have not received my soaring magazine yet this month
>>but I hear there
>> is an article dealing with fin mounted vs fuselage
>>mounted TE probes.
>>
>> Anyone have thoughts on this issue?
>>
>> Richard
>> www.craggyaero.com
>>
>
>I read Dick's article with interest. He did his usual
>incredibly through
>experimental work to support the probe design.
>
>I see several advantages to the Johnson probe.
>
>1. It's likely to be less sensitive to yaw with its
>single hole aft.
>2. Shorter tubing runs that can be easily inspected
>and replaced if needed.
>3. It eliminates the danger of breaking the fin mounted
>probe while
>installing/removing the tail dolly.
>4. Possibly faster and more accurate vario response
>since acceleration and
>line capacity errors are reduced.
>5, One less part to install (or forget)
>
>Bill Daniels
>
>

[For Example John Smith]

This placement was suggested for the PW5 I used to be a partner in.
Installation was simple and it worked as well as the fin implementation on
my Mosquito.
> wrote in message
oups.com...
> I have not received my soaring magazine yet this month but I hear there
> is an article dealing with fin mounted vs fuselage mounted TE probes.
>
> Anyone have thoughts on this issue?
>
> Richard
> www.craggyaero.com
>

[[email protected]]

On my LS-6 I have a small TE Leak somewhere between the bottom of the
Vertical Stabilizer and the TE Probe that's located on the upper
leading edge of the Vertical Stabilizer. The leak is most likely where
the tubing connects to the TE Probe. I think that I would need to cut a
hole in the Vertical Stabilizer to fix it! UGGHH!!!

This Fuselage mounted TE Probe would be a perfect fix for my situation.
My questions are: How do you know where to place the probe on a
particular aircraft? How come nobody figured this sysytem out sooner.
Are there any down sides to this system??

[[email protected]]

On my LS-6 I have a small TE Leak somewhere between the bottom of the
Vertical Stabilizer and the TE Probe that's located on the upper
leading edge of the Vertical Stabilizer. The leak is most likely where
the tubing connects to the TE Probe. I think that I would need to cut a
hole in the Vertical Stabilizer to fix it! UGGHH!!!

This Fuselage mounted TE Probe would be a perfect fix for my situation.
My questions are: How do you know where to place the probe on a
particular aircraft? How come nobody figured this sysytem out sooner.
Are there any down sides to this system??

Thanks for Any replies!

Jerz

[Bob Johnson]

For Example John Smith wrote:
> This placement was suggested for the PW5 I used to be a partner in.
> Installation was simple and it worked as well as the fin implementation on
> my Mosquito.
> > wrote in message
> oups.com...
>
>>I have not received my soaring magazine yet this month but I hear there
>>is an article dealing with fin mounted vs fuselage mounted TE probes.
>>
>>Anyone have thoughts on this issue?
>>
>>Richard
>>www.craggyaero.com

Hey, and how about those way cool wing root fairings! I don't believe
they are standard fare on S-H Venti A or B. Their lack is the biggest
lapse in the design IMHO.

Does anyone remember an article on this mod?

And congratulations to Dick for a timeless contribution to the science
and art of TE and all the other great work he has done for us. Gratis.

Bob Johnson

[stephanevdv]

I won't receive my copy of "Soaring" until some weeks from now, so I
don't know exactly what's in it, and can merely make an educated guess
based on the comments in this thread, but:

1) > It eliminates the danger of breaking the fin mounted probe while
> installing/removing the tail dolly. On the original ASW-19 and -20, there is a fuselage mounted TE probe.
Every single one I know has been bent or broken very soon after
delivery, and repeatedly repaired or changed. One I made myself has
been bent during the first half hour after mounting, while I was away
preparing my navigation. So much for the breaking risk. People just
love to step over a fuselage instead of going around.

2) Of course, these ASW probes are placed some distance behind the
wing. You could avoid the breaking problem by placing the probe above
the wing, but I remember distinctly some articles by different TE probe
designers warning against this placement because this would influence
the results negatively, due to the underpressure over the wing. If
Dick's findings disprove this belief, he will have rendered us glider
pilots another great service.


--
stephanevdv
------------------------------------------------------------------------
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[[email protected]]

The Ventus A and B models really need a good wing root fairing.
Schempp-Hirth realized their mistake years ago, and offered a simple
aftermarket fiberglass fairing mod kit. I installed mine during the
early 80s, and it really helped the low speed performance.
I think it may still be possible to obtain a similar fairing, and
possibly Al McDonald or someone else knows where?
Dick Johnson