Hi Bill,
Point well taken.
I should have been more specific in my suggestion...yes, I was
envisioning properly drilling out those existing rivets as would then
also secure the stainless "overskinning" (as is also necessary to
install the stainless overlapping the fore and aft formers through
which rivets are applied).
In the past, some have believed that Cherry rivets are not part of the
ERCO-approved drawing which one
is expected to follow in converting a C to a D model. To use "normal"
rivets requires the removal of the fuselage tank, which is a
considerable effort and expense.
Is was in comparison to this scenario that I suggested the overskinning
since (1) the model is not being changed, (2) safety is enhanced, cost
is reduced and (3) more people are likely to do it if a logbook
signoff is sufficient documentation considering that Cherry rivets now
exist and use of same for such
purpose is "acceptable to the Administrator".
Regards,
WRB
--
On Jul 30, 2009, at 13:04, Bill BIGGS wrote:
It is actually almost as easy to remove the existing aluminum skin, us
it as a pattern, and fabricate and install new stainless skin using
the same rivet holes, then make appropriate logbook entry.
Our friends at the FAA take a dim view of adding additional holes to
a structure, and because the "patch" would be over 6" square would be
considered a major repair and require atleast a 377 and perhaps DER
approval. (seeXXII on attachment)
Bill
To: [email protected]
From: [email protected]
Date: Thu, 30 Jul 2009 11:38:22 -0500
Subject: Re: [ercoupe-tech] stainless steel skin
Hi Linda,
Yes it is a safety issue big-time.
...simply
adding a stainless covering to the existing aluminum with cherry
rivets. The fire
protection is identical but this process was never factory or FAA
-approved as
an option when converting a C to a D model.
Since the 1320 lb. STC does not do this, and since the addition of such
stainless
protection is obviously desirable from a safety standpoint and does not
in any
manner adversely affect the structure of the upper forward fuselage it
would be
my humble opinion that addition of the stainless panel over the
existing aluminum
sheeting should be considered a "minor modification" and relatively
simple to do
within the existing regulatory framework, but I'm no mechanic.
That said, nothing is "easy" anymore when dealing with the FAA unless
you
"know somebody".
Regards,
WRB
