Thanks for the FAA opinions on continuing to use the old service manual without the prohibition.
Update is that the IA is still unwilling to sign the annual, claiming that because it is a control surface it automatically counts as a “major repair” requiring a 337, while the shop that did the original repair appears to have treated it as a minor repair under AC 43-13 and never filed a 337. I’ve been looking through the FARs on this and it seems to me that it does not meet the standard for being a major repair, but because it’s so open to the IA’s discretion it’s not indisputably a minor repair. They got an opinion from Piper that it is still “not approved” regardless of the service manual thing (I suspect some CYA there) but it could be done by an IA with a 337, and from their point of view that is the final answer.
Unless someone has an explicit legal opinion from the FAA that a control surface patch can be a minor repair done under the authority of AC 43-13 and does not require a 337?
(Unfortunately the flight school that did the original repair is no longer accepting outside customers for repair work so taking it back to them is not an option.)
