On May 3, 6:05*pm, T wrote:
On May 2, 7:40*am, Greg Arnold wrote:

The local towplane operation has a Pawnee that back in 1996 had an STC
from STC Inc. (SA01154AT) modification to the wing attach cluster.
Apparently it still requires a wings off inspection every two years.
The owner of the operation has heard that there may be an inexpensive
permanent fix that eliminates the biennial inspection. *Perhaps a gusset
plate welded onto the cluster. Is anyone familiar with that procedure?

Our wing attach cluster STC repair came from Schweizer and requires
annual inspections, but only the wing removal and dye check ever 6
years. It's not that hard to remove Pawnee wings if you have a hanger
and an engine hoist.

You can research STCs on FAA.gov.

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgSAIB.nsf/2d69931bd1dab16b862572250070589f/c1850358cba7bf4a8625721f0052ec5c/$FILE/ACE-96-10.pdf

There are only 3 STCs I could find that are approved for the Wing
Cluster AD.
SA00992AT, Kosola Assoc, Georgia
SA01073AT, Schweizer Aircraft (the one we have mentioned above)
SA01154AT, STC Inc, (the one you say you have)

And I would think that once one of the STCs is installed, it would be
very difficult to change to a different one because of all the welding
that is done on original installation.