Tom,
I understand the frustration you must feel, and yet it is likely the
result of many trying
to oversimplify a discussion that requires precise words and
understanding of those words.
It helps if everyone will start from and maintain the presumption that
no one volunteering
assistance wants anything other than the quickest, simplest and most
inexpensive resolution
to your problem and gets any compensation other than such gratitude as
may be earned.
First off, your problem is with the rear spar. Reinforcement of the
rear spar is covered in
detail in Ercoupe Service Memorandum No. 53A. Hartmut's attachment did
not come thru
(for me). Not having been personally involved with such, I was
surprised by suggestions
that airframe alignment could be affected by rear spar work; and others
now discussing
main spar work seem to have been similarly led mentally astray.
Ed is right that ERCO made and sold "state of the art" aircraft
production machinery long
before they made and sold the Ercoupe. While it is true the first ten
Ercoupes were hand
built, even then every attempt was being made to standardize parts and
assemblies.
The level of standardization achieved in the first 112 (prewar)
airframes was totally
eclipsed by postwar airframes because wartime government contracts to
produce gun
turrets and other warbird accessories and components had enabled ERCO
to acquire
(at government expense) extensive machinery for automated sheet metal
work, and
their design and engineering capability was very, very good.
There are three possible "John"s in this discussion, which can confuse.
I don't think
John Wright Jr. (commonly considered the "man" for fuel tank repair,
but fully capable
beyond that) has been involved. I would suggest that ERCO's production
sophistication
and expertise would suggest that John Wright Sr.'s belief that purchase
of a good used
pre-drilled assembly is the best way to proceed.
It would appear that buying a new piece and drilling it to fit (in
place without the jigs that
ERCO used to pre-drill parts before final assembly) could result in the
sort of
misalignment Paul Anton (an IA) ascribed to an unidentified Alaskan
coupe airframe;
therefore use of a pre-drilled used unit would allow "adjustment" of
support pressure
on the airframe as a means of MAKING the holes line up as they should.
An expert understanding all of this could be willing to undertake it,
but unwilling to invest
the uncompensated time necessary for an owner to make an informed
choice as to how
to proceed...sort of "I'll do it, but you have to just trust me" ;<)
I, personally, seldom have
such trust in anyone.
I don't see any "black hats" here, but a continuing need for mutual
respect and patience.
Best regards,
William R. Bayne
.____|-(o)-|____.
(Copyright 2009)
--
On Jan 16, 2009, at 13:04, Hartmut Beil wrote:
Tom
Service Bulletin covers in detail how to replace a rear spar.
I attach the file for you and others that might not have access to
the Service Bulletins right now.
Hartmut
