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RE: Europa-List: Rear wing root socket problems

Subject: RE: Europa-List: Rear wing root socket problems
From: Bud Yerly <budyerly@msn.com>
Date: Mon, 7 Sep 2020 13:31:52
Sorry to hear of your issues.

The failure of the socket indicates the crash may have been more severe tha
n anticipated.
In all my years, I=92ve seen corrosion on older socket parts that were not 
as well protected as the new bits are.  I have never seen a failure in the 
26A as this was a well engineered and tested part by Europa.  If installed 
backwards, this can happen.

Please contact Europa Aircraft because the W26 part assembly has not been a
n issue and replacement of the corroded items may be smart.  This area is a
 critical flight component and the annual inspection and repair may have mi
ssed this part may have been damaged or assembled incorrectly.  If the sock
et inner W26B failed, was the interior tube and attachments properly instal
led, checked and inspected is the question.

Loctite is between the barrel and that thin rectangular piece you call it s
o they operate as a unit.  The wing pin goes into the fully assembled socke
t and allows it to move up and down just a bit.  If not Loctited the barrel
 can rotate and make pin insertion more difficult.  (Frankly, during wing i
nstall, simply note the orientation of the barrel is all that is needed.) N
ote that the assembly thin side goes on the fuselage side.  Don=92t get tha
t backwards as it builds up stress and may be a part of the failure you see
.

As far as the structural strength, the yoke piece 26A and the barrel 26C ca
rry the load of the wing pulling forward under max G load.  This barrel is 
designed to move up and down.

As for the Rotax 914:
There is a long and boring troubleshooting guide on my website on keeping t
he 914 running true.  The carbs are easily rebuilt with proper attention to
 detail.  I find the Rotax engine forum informational, but doesn=92t cover 
in enough detail.  I do find the videos provided by Rotax to be quite compl
ete.  The paper I did covers various phases and expands troubleshooting.  S
ee the techniques section for an updated version since published in the Eur
opa Club magazine.

Bud Yerly
www.customflightcreations.com
Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Window
s 10

From: Erik Dahlb=E4ck<mailto:erik@erikdahlbeck.com>
Sent: Sunday, September 6, 2020 5:18 PM
Subject: Europa-List: Rear wing root socket problems

Hello,

First time posting here, hoping my attached photos are small enough, etc...

I'm trying to get Europa SE-XRX airworthy again after being grounded for
two years. At first due to some hard-to-diagnose carburettor problems.
914 float bowls, enough said... If interested, I have a post about it
over at Rotax-Owners:
https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.rot
ax-owner.com%2Fen%2F912-914-technical-questions%2F6881-914ul-carburettor-gr
emlins%3Fstart%3D15&amp;data=02%7C01%7C%7C8482b0ef213641821e7208d852aa5b7
2%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637350238926500351&amp;sdata
=pMvGV5%2BI41Zjnn3nQnSV8Wo37dGxDwnn9%2Ff%2Bu5P7T%2F0%3D&amp;reserved=0


PROBLEM NO 1

Anyway, after fixing the engine and while doing the annual together with
the previous owner/builder, it was discovered that the rear wing socket
housing, part W26B, starboard side, was cracked in two parts. Further
inspection showed that also the port side was cracked, albeit not having
split in two just yet. Please see attached photos.

I've got the spares from the manufacturer however, I'm curious if this
is a known problem? Any thoughts on what could be the cause? Anything
further to look out for?

My local mechanic seemed just as puzzled as I was when looking at how
thin this part is. I mean what is it, 2 mm?

One thing to consider: The aircraft was built as a monowheel but crashed
on takeoff during flight testing, making a hard landing and a ground
loop. The incident was traced to a construction error in the control
line attachment to the rudder, causing alterations in the design (some
of might be familiar with this). The aircraft was then repaired (by some
sailplane workshop that seemed to know what they were doing, I've seen
the photos at least). Among other things it got a new tail, a CS prop
and was rebuilt as a trigear. Might this new discovery simply be residue
of that old incident?

Also, the builder's manual states that the W26B and C parts should be
loctited together. However, there was no trace of this. I'm not sure if
that instruction has been there since the beginning or if it could be a
later revision? However, I sort of have my doubts as to some loctite
being able to strenghten this construction enough to not break from
whatever broke this...?

Finally, any thoughts on how to reassemble these parts? Where does the
Loctite go? Just on the barrel and make sure the holes align before i
dries? How to you avoid getting loctite on the surfaces between the
barrel and the socket body (W26A)?


PROBLEM NO 2

Due to various reasons, I only got around to cleaning the grease off the
rear socket assemblies, in preparation for reassembly, but doing the
loctite-work in a cold hangar, etc, and also enlisting the help of the
very busy local mechanic, was more than I could get done before last winter
.

Now, on inspection, the W26A socket bodies show signs of corrosion.
Please see the other attached photos. Anyone have an opinion on just how
bad this is? Do they also need changing? And does that require
composite-work? I've been looking through the builder's manual but I'm
afraid I'm not quite up to understanding all of it.


Any thoughts on both of the above issues would be greatly appreciated!


Sincerely,

Erik Gunneland Dahlb=E4ck
Link=F6ping, Sweden
Europa SE-XRX



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