The Coupe is of SEMI-monocoque construction.  Some parts of the skin lend
little structural strength.  Some provide the sole structural support.  I
believe the "jowl cowling" is what we are talking about, and your
observation is, in my experience, correct.  The little dent  is not unusual,
and seems to be associated with evidence of impact in the nose area.  I
always guessed it to be the result of slamming the nose down and collapsing
the old single-fork nose gear.

 

Fortunately, the jowl cowling only supports the jowl cowling.  The little
"buckle" line or wave may be something you can just pop out and brace a bit.
Or, if you have access to the skills, run it through an English Wheel to
smooth it out.  But, be careful.  My cowling still shows evidence of my lack
of finesse on the English Wheel.

Dave Winters

 

 

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http://WintersPatentLaw.com

 

From: [email protected] [mailto:[email protected]] On
Behalf Of Roy Stubbs
Sent: Monday, May 11, 2009 10:09 AM
To: [email protected]; [email protected]
Subject: RE: [ercoupe-tech] Re:New to Ercoupe Tech Group - Question Re:
Fuselage Skin Buckles Fwd o

 






To add to Chris' remarks, remember the Ercoupe is of monocoque construction.
The fuselage skin supports some or most of the load.  Wrinkles I think would
be bad.

 

  _____  

From: [email protected] [mailto:[email protected]] On
Behalf Of ALAN FAIRCLOUGH
Sent: Monday, May 11, 2009 10:51 AM
To: [email protected]
Subject: [ercoupe-tech] Re:New to Ercoupe Tech Group - Question Re: Fuselage
Skin Buckles Fwd o
Importance: Low

 








Chris:

 

You are not clear enough about where the slight buckling is;

Two possibilities:

 

A) It is the wing root fairing that is wrinkled. If this is the case, it can
be repalced. It is not a structural component and has no effect on flying
the plane.

 

B) It is the side wall of the aircraft that is buckled and as part of the
structure of the plane is usually buckeld because of a collapsed nosewheeel
or similar hard landing. An A&P would have to decide if it is airworthy or
not.

 

As an important part of checking a coupe's frame for indications of hard
landings here are a few things to look for:

 

A) The bottom of the firewall can have some serious wrinkling which could
indicate a nose in.

 

B) The two sort of triangular panels under the plane between the walkway and
the belly of the plane will show wrinkles indicating one of the wings being
pused backwards or a MLG that hit something. Inspect the rear spar on the
inside of the spar cap attachment for buckling.

 

C) wrinkles on the wing root fairing which may indicate it has been damaged
and sort of flattened out again to be re-used rather than replaced. Not
structurally dangerous but a good reason to inspect further.

 

D) Wrinkles on the top end of the tailcone are usually due to the tail being
pushed down. only the bolts holding the horizontal stabilizer are approved
push down points. These wrinkles do not relate to hard landings.

 

E) Misalignment between the wings and the horizontal stabilizer. While the
wings have a dihedral and the stabilizer is flat, seen from behind, the
stabilizer height on both sides of the plane must match corresponding points
on both wings. Wing angle has some minor adjustement at the wing attachment
bolts but at most you can move wingtips up and down about two inches. A
larger difference could indicate a twisted main spar. 

 

Alan Fairclough

N87333

N94694

 



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