What about the bottom weld points? Would it hurt to put in pieces here
also?
Gary leinberger
A237
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Roger Bull
Sent: Friday, January 19, 2007 3:42 PM
Subject: RE: Europa-List: Mod 72 question
O.K. Bob, you woke me up!
Rob Housman's answer is on the ball. Using Redux would necessitate
increasing the clearance between the original tube and the new inserts.
The Redux would not be strong enough to withstand the bending load,
which is the critical part of the overall stress. The insert is
intended to be a close but not interference fit in the outer tubes after
reaming. Any small clearance which may exist after fitting the new
tubes will be taken up by deflection caused by the initial load applied
by the weight of the engine and propeller.
The bending load is applied both by the vertical load from the weight of
the engine acting some 2.5" approx forward of the weld affected area,
and also by the small tube which is about 1" above the main horizontal
tube. The forward thrust from the propeller creates this bending load.
To that has to be added on one side the torque reaction. (Distances are
---From memory as I am writing this fom home).
I have made a small change to the Mod leaflet to make the applicability
criteria a little clearer. The factors which affect applicability are
engine and propeller weights and c's of g forward of the undercarriage
mounting frame, and the engine torque.
Briefly all Rotax engined Europas, except those with classic engine
installations and light propellers as defined in the Mod leaflet, will
need to incorporate the Mod. So all Rotax engined XS models, regardless
of whether 912, 912S or 914, and regardless of propeller will need the
Mod.
Europas with engines other than Rotax will need to be checked on a case
by case basis. We have already established that Europas with the Jabiru
3300 engine will need the Mod.
It was orginally intended that the news of the Mod would be promulgated
by the PFA and EA4 on their respective websites simultaneously -
unfortunately that did not happen. The PFA have now updated their Type
Acceptance Data Sheet to include Mod 72.
We realise that quite a long time has elapsed since the failure took
place that gave rise to this Mod. It was necessary first to establish
that the failure was not a one-off due to a unique set of circumstances;
research into the original calculations established that there was a
more general problem. The we had to devise a satisfactory solution that
would be reasonably straightforward to incorporate, then carry out tests
to prove the fix. Then the method had to be agreed with the PFA, and
the Mod leaflet written. This latter exercise proved rather drawn out,
and several drafts were needed before the current version was agreed.
Establishing why the original error in stressing was made during the
reign of EMIL proved almost impossible, as the engineer concerned died a
few years ago.
I realise that many people may feel that an unnecessary fuss is being
made about this Mod, but a look at the attached photo of the first, but
not only, failure should prove interesting.
Best regards,
Roger Bull
EA4
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com]On Behalf Of Robert
Borger
Sent: 19 January 2007 1:48 pm
Subject: Europa-List: Mod 72 question
Fellow Europaphiles,
The Mod 72 topic has become too quiet. I've decided to give it a poke
and see if I can wake it up again.
I have all the various bits for Mod 72 on order. Etching primer,
ACF-50,
16.5 mm hand reamer & Mod 72 kit.
I am wondering why the heavy wall tubing is not bonded in place with
something like Redux.
Is the press fit good enough to support the frame?
Would it be better to Redux the insert in place? Better support and
corrosion protection?
If not, why not?
Good building and great flying,
Bob Borger
Standing by, wearing my nomex undies, ready for the flames.
P.S.
The reamer will be available for loan to any Europa builder in the U.S.
or Canada who needs it for Mod 72.
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