Proper Way to Insert Multi-Probe

On Thursday, February 15, 2018 at 10:47:02 AM UTC-5, Matt Herron Jr. wrote:
On Thursday, February 15, 2018 at 7:24:24 AM UTC-8, Dan Marotta wrote:
When I got my Stemme, I asked my instructor if there was a proper
technique to insert the multi-probe in the nose.Â* He said to just push
it in until I hear/feel a metallic click.Â* That's worked just fine for
the past two years but I wonder if I should lubricate the thing, say
with Vaseline or something.Â* I shudder to think of replacing internal
o-rings.
--
Dan, 5J

Pinch your nose to get some skin oils on your fingers, and wipe the probe.. Just enough lubrication, and readily available! Works like a charm.

I do the same thing. I also put a wrap of white tape just at the edge of the socket as a witness to make sure it is in all the way.
UH

Yep, agreed.
Store the probe so it stays clean (lot of times we use one of the ASx side cockpit vents, also helps keep peeps from dropping something on it.....), wipe it off a few times a year, very thin smear of lube, twist while installing.
Yes, the "witness mark" tape is nice. If for some reason the probe sorta "hangs" on install, you may have a huge system leak/cross talk if it's not fully seated. Yep, did a spring flight like that once, helped fine tune my butt vario...... Just twist it in until the tape is against the tube in the fin, align the angled probe as required (some say straight up, some say straight down....).

There are clear instructions by ESA at
https://tinyurl.com/ESAFAQEnglish
which suggest cleanliness, light lubrication, and give
orientation advice also. Just saying.

At 19:28 15 February 2018, Charlie M. UH & 002
owner/pilot wrote:
Yep, agreed.
Store the probe so it stays clean (lot of times we use
one of the ASx side
=
cockpit vents, also helps keep peeps from dropping
something on it.....),
w=
ipe it off a few times a year, very thin smear of lube,
twist while
install=
ing.
Yes, the "witness mark" tape is nice. If for some reason
the probe sorta
"h=
angs" on install, you may have a huge system
leak/cross talk if it's not
fu=
lly seated. Yep, did a spring flight like that once, helped
fine tune my
bu=
tt vario...... Just twist it in until the tape is against the
tube in the
f=
in, align the angled probe as required (some say
straight up, some say
stra=
ight down....).

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

Ah Ha! Oriented UP!


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

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

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?

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.

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.

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?