A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Soaring
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Prandtl multi probe receptacle used for TE only?



 
 
Thread Tools Display Modes
  #1  
Old February 15th 18, 12:03 AM posted to rec.aviation.soaring
Matt Herron Jr.
external usenet poster
 
Posts: 548
Default Prandtl multi probe receptacle used for TE only?

I have a Prandtl type receptacle in the fin of my ASW27. The previous owner converted to to TE probe only, by tying off the static and pitot lines behind the panel. Anything wrong with this set-up? I guess there would be more potential for leaks, at a minimum. will the extra volume of air connected in the unused tubes create any adverse effects on the TE line? I get my static from the ports on the boom about 2/3 back.

Thanks for any input.

Matt
  #2  
Old February 15th 18, 12:44 AM posted to rec.aviation.soaring
Dave Nadler
external usenet poster
 
Posts: 1,610
Default Prandtl multi probe receptacle used for TE only?

Hi Matt!

On Wednesday, February 14, 2018 at 6:03:47 PM UTC-5, Matt Herron Jr. wrote:
I have a Prandtl type receptacle in the fin of my ASW27.
The previous owner converted to to TE probe only, by tying off the static
and pitot lines behind the panel. Anything wrong with this set-up?
I get my static from the ports on the boom about 2/3 back.


You mean a 3-way probe, right?
The probe pitot and static are better than fuselage ports (though pitot
is easily wiped out by a bug). If your instrumentation is working OK with
fuselage ports, why mess with it?

I guess there would be more potential for leaks, at a minimum.


Nope.

will the extra volume of air connected in the unused tubes create
any adverse effects on the TE line?


No, they are not connected in any way.


See ya, Dave
  #3  
Old February 15th 18, 12:57 AM posted to rec.aviation.soaring
JS[_5_]
external usenet poster
 
Posts: 624
Default Prandtl multi probe receptacle used for TE only?

On Wednesday, February 14, 2018 at 3:44:59 PM UTC-8, Dave Nadler wrote:
Hi Matt!

On Wednesday, February 14, 2018 at 6:03:47 PM UTC-5, Matt Herron Jr. wrote:
I have a Prandtl type receptacle in the fin of my ASW27.
The previous owner converted to to TE probe only, by tying off the static
and pitot lines behind the panel. Anything wrong with this set-up?
I get my static from the ports on the boom about 2/3 back.


You mean a 3-way probe, right?
The probe pitot and static are better than fuselage ports (though pitot
is easily wiped out by a bug). If your instrumentation is working OK with
fuselage ports, why mess with it?

I guess there would be more potential for leaks, at a minimum.


Nope.

will the extra volume of air connected in the unused tubes create
any adverse effects on the TE line?


No, they are not connected in any way.


See ya, Dave


The three circuits are not supposed to be connected, but if there is a bad O-ring, all bets are off.
In a perfect world, your system as plumbed will work fine. If the mod was done due to crosstalk, and there is a leak in the plugged static or pitot lines, it will be erratic.
After the lines were disconnected and plugged, there's a chance nobody has leak checked them.
They're a pain to replace. I have a spare fitting for ASW27/28/29 at home, hope to never need it. Fortunately my leak was found to be two things, a bad probe and a hidden connector in the back of the panel, which Rex found instead of replacing the fitting.
Jim

  #4  
Old February 15th 18, 02:24 AM posted to rec.aviation.soaring
Matt Herron Jr.
external usenet poster
 
Posts: 548
Default Prandtl multi probe receptacle used for TE only?

On Wednesday, February 14, 2018 at 3:57:27 PM UTC-8, JS wrote:
On Wednesday, February 14, 2018 at 3:44:59 PM UTC-8, Dave Nadler wrote:
Hi Matt!

On Wednesday, February 14, 2018 at 6:03:47 PM UTC-5, Matt Herron Jr. wrote:
I have a Prandtl type receptacle in the fin of my ASW27.
The previous owner converted to to TE probe only, by tying off the static
and pitot lines behind the panel. Anything wrong with this set-up?
I get my static from the ports on the boom about 2/3 back.


You mean a 3-way probe, right?
The probe pitot and static are better than fuselage ports (though pitot
is easily wiped out by a bug). If your instrumentation is working OK with
fuselage ports, why mess with it?

I guess there would be more potential for leaks, at a minimum.


Nope.

will the extra volume of air connected in the unused tubes create
any adverse effects on the TE line?


No, they are not connected in any way.


See ya, Dave


The three circuits are not supposed to be connected, but if there is a bad O-ring, all bets are off.
In a perfect world, your system as plumbed will work fine. If the mod was done due to crosstalk, and there is a leak in the plugged static or pitot lines, it will be erratic.
After the lines were disconnected and plugged, there's a chance nobody has leak checked them.
They're a pain to replace. I have a spare fitting for ASW27/28/29 at home, hope to never need it. Fortunately my leak was found to be two things, a bad probe and a hidden connector in the back of the panel, which Rex found instead of replacing the fitting.
Jim


I agree in normal use the three lines are not connected. However, if you just insert a TE probe into the multipart receptacle then all three ports share the same flow because the TE probe doesn't go deep enough and is not stepped like the Prandtl probe.
  #5  
Old February 15th 18, 03:00 AM posted to rec.aviation.soaring
Dave Nadler
external usenet poster
 
Posts: 1,610
Default Prandtl multi probe receptacle used for TE only?

On Wednesday, February 14, 2018 at 6:57:27 PM UTC-5, JS wrote:
They're a pain to replace.


Yup, IMHO a huge design blunder to put the O-rings in the socket
instead of on the probe. I once asked SH how to replace the O-rings,
and they said they have absolutely no idea ;-(
  #6  
Old February 15th 18, 08:39 AM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 374
Default Prandtl multi probe receptacle used for TE only?

How to change the internal O-rings is all explained in the service section of the ESA Systems web page. That's not to say it is easy - or even possible in the case of ring 3 without removing the socket which means cutting open the fin.

  #7  
Old February 15th 18, 09:36 AM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 83
Default Prandtl multi probe receptacle used for TE only?

The probes and sockets are produced by esa-systems in Berlin. There's an instruction on how to replace the O-rings on their website: https://www.esa-systems.com/en/suppo...i-change-them/
  #8  
Old February 15th 18, 02:29 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 266
Default Prandtl multi probe receptacle used for TE only?

Now tell me again...
Why aren't the O rings on the probe?

Must be an oversupply of engineers needing to design something like this O ring insertion tool.
  #9  
Old February 15th 18, 02:52 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 83
Default Prandtl multi probe receptacle used for TE only?

Don't ask me.

There are two videos on YouTube explaining the process: https://www.youtube.com/watch?v=NitQF9Of4fk https://www.youtube.com/watch?v=a91LM2JIF0s
  #10  
Old February 15th 18, 03:12 PM posted to rec.aviation.soaring
krasw
external usenet poster
 
Posts: 668
Default Prandtl multi probe receptacle used for TE only?

torstai 15. helmikuuta 2018 1.03.47 UTC+2 Matt Herron Jr. kirjoitti:
I have a Prandtl type receptacle in the fin of my ASW27. The previous owner converted to to TE probe only, by tying off the static and pitot lines behind the panel. Anything wrong with this set-up? I guess there would be more potential for leaks, at a minimum. will the extra volume of air connected in the unused tubes create any adverse effects on the TE line? I get my static from the ports on the boom about 2/3 back.

Thanks for any input.

Matt


Volume of triple pneumatic tube from tail to panel might be close to half of variometer flask volume, so answer is "maybe" even in theoretical world. But there is too many variables in pitot-static system to give you systematic answer.
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Prandtl Flying Wing Testing by NASA [email protected] Soaring 2 March 24th 16 07:55 PM
military spec receptacle MIL-C-24368/2 [email protected] Naval Aviation 0 June 30th 08 05:53 PM
Multi - probe KP Soaring 1 March 7th 05 07:03 PM
Discus Prandtl tube Serge Serfaty Soaring 5 October 6th 04 08:48 AM


All times are GMT +1. The time now is 02:55 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AviationBanter.
The comments are property of their posters.