AD 2002-26-02 Center Section Spar Corrosion Inspection

Ahhh haaah...Thanks Larry, the last sentence helps, but is strangely unsatisfying...Maybe some logic should find it's way into these rabbit holes, aka regulations.

Edd,
Forgive me if I'm being obtuse...So you are confirming that once a C is converted to a D, it can't be reverted to it's original stock configuration? I don't understand why...Please advise.

Thanks
Brian

Brian: You are correct.
Succinctly, my aircraft that had gone thru a many year restoration was being prepared to go on the market by different mechanic. A paper work audit revealed that it had never been converted to a D model prior to the 0-200 installation. The 0-200 STC conversion was applicable only to the D model.
A field approval was applied for, keeping the C model, but using examples of previously approved conversion that referenced the D model data, Atlanta ACO approved the request. Increase in weight to LSA limit was completed by Alpha STC..
Strictly a happenstance event

Edd

Edd,

I have been told that once a C is converted to a D it can't be changed back to a C. What does it take to retain the C status for LSA as you mentioned you did?

I recently did a annual on a F-1A and had we not pulled the wing, we would not have found the exfoliation corrosion that was on the upper spar cap under the wing attach fitting.