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

Proper Way to Insert Multi-Probe



 
 
Thread Tools Display Modes
  #11  
Old February 15th 18, 09:46 PM posted to rec.aviation.soaring
kirk.stant
external usenet poster
 
Posts: 1,260
Default Proper Way to Insert Multi-Probe

On Thursday, February 15, 2018 at 2:30:07 PM UTC-6, Steve Thompson wrote:
There are clear instructions by ESA at
https://tinyurl.com/ESAFAQEnglish
which suggest cleanliness, light lubrication, and give
orientation advice also. Just saying.


Ah Ha! Oriented UP!

Let the arguing - and bogus explanations - begin!

(FWIW I've always been in the UP camp...position relative to the horizontal, angle of the probe when changing AOA, less chance of hitting it when installing tail dolly...)

Kirk
66
  #12  
Old February 15th 18, 10:54 PM posted to rec.aviation.soaring
Dave Springford
external usenet poster
 
Posts: 320
Default Proper Way to Insert Multi-Probe



Ah Ha! Oriented UP!



Of course it goes up - it's more virile.
  #13  
Old February 17th 18, 12:14 AM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 145
Default Proper Way to Insert Multi-Probe

On Thursday, February 15, 2018 at 12:46:27 PM UTC-8, kirk.stant wrote:
On Thursday, February 15, 2018 at 2:30:07 PM UTC-6, Steve Thompson wrote:
There are clear instructions by ESA at
https://tinyurl.com/ESAFAQEnglish
which suggest cleanliness, light lubrication, and give
orientation advice also. Just saying.


Ah Ha! Oriented UP!

Let the arguing - and bogus explanations - begin!

(FWIW I've always been in the UP camp...position relative to the horizontal, angle of the probe when changing AOA, less chance of hitting it when installing tail dolly...)

Kirk
66


I used to always put my probe up (whenever I had the opportunity), but then someone pointed out to me that when the probe is installed down and the glider is in flying position, the probe is quite close to vertical. Seemed that was likely the correct position.
  #14  
Old February 17th 18, 08:37 AM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 374
Default Proper Way to Insert Multi-Probe

The typical designed probe is designed to point up which gives the intended angle to the airflow and also keeps the tip high and as close to the line of the tailplane. See Rudy Brozel's articles.

Another quite common factor is to avoid the down pointing probe interfering with a fin pitot which is often close below. Dick Johnson tested this and showed that there was significant interference.
  #15  
Old February 17th 18, 09:44 AM posted to rec.aviation.soaring
krasw
external usenet poster
 
Posts: 668
Default Proper Way to Insert Multi-Probe

On Saturday, 17 February 2018 01:14:48 UTC+2, wrote:

I used to always put my probe up (whenever I had the opportunity), but then someone pointed out to me that when the probe is installed down and the glider is in flying position, the probe is quite close to vertical. Seemed that was likely the correct position.


I'm confused. The adapter for the probe is pointing straight to airflow at flying angle-of-attack. The probe end sticking up or down would have same angle relative to airflow?
  #16  
Old February 18th 18, 11:15 AM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 77
Default Proper Way to Insert Multi-Probe

Most compensation probes are designed to function with an angle of 70°, not 90° (but some do), between the prong and the airflow. Whatever you do, that angle will change whenever you increase or reduce your airspeed, so the system must have some built-in flexibility. How much flexibility and in what direction (up or down) will probably depend on the design of the probe. So follow the instructions of the manufacturer, would be my advice. ESA Systems says prong up, so that's it for me.

There are two-pronged probes that should be placed with the prongs horizontal.
https://www.esa-systems.com/en/produ...e-dnst-840-mm/
https://www.esa-systems.com/en/produ...robe-dnstatek/
According to a German study, this type gives the best compensation results.
  #17  
Old February 18th 18, 02:49 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 2,124
Default Proper Way to Insert Multi-Probe

On Thursday, February 15, 2018 at 4:54:24 PM UTC-5, Dave Springford wrote:

Ah Ha! Oriented UP!



Of course it goes up - it's more virile.


Aside from virility raising the sensing point by another 6 inches gets it further above the turbulence coming off the wing root, especially at low speed and high angle of attack.
Also less likely to catch it when removing the tail dolly.
UH
  #18  
Old February 19th 18, 01:44 AM posted to rec.aviation.soaring
TomNau
external usenet poster
 
Posts: 5
Default Proper Way to Insert Multi-Probe

This may be a silly question, but isn’t there only one way for it to be oriented correctly for the ports to line up properly?
  #19  
Old February 19th 18, 02:31 AM posted to rec.aviation.soaring
Charlie M. (UH & 002 owner/pilot)
external usenet poster
 
Posts: 1,383
Default Proper Way to Insert Multi-Probe

No, the O-rings seal sections of the tube in the fin, the ports in the probe just empty into that section.
 




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 multi probe receptacle used for TE only? Matt Herron Jr. Soaring 12 February 15th 18 09:32 PM
Proper Std. Cirrus class Jacopo Romei Soaring 4 January 9th 17 08:57 PM
I will be insert usenet Mark Piloting 2 October 10th 10 12:32 PM
Multi - probe KP Soaring 1 March 7th 05 07:03 PM


All times are GMT +1. The time now is 05:45 AM.


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