I have been working on the left wing in my garage since the space was vacated buy the fuselage. The wing was bent outboard of the factory spar splice in the ground loop executed by the previous owner.
After removing the damaged areas and inspecting the damage I had decided to repair the spar. After coming up with a repair plan I contacted my local and familiar FAA representative to discuss whether a field approval would be required for my repair plan.
As it turns out the spar caps were not damaged, only the spar web and the associated upper flange. For information in our discussion I referenced the 100 series 1963 and prior maintenance manual, which does not apply, to our 170,s.
The 100 series maintenance manual outlines a very complicated spar repair that actually replaces sections of the afore mentioned spar caps which as stated were not damaged. I explained that my repair was actually less complicated as it did not include an insertion repair to the spar caps.
The following are the comments by my FAA rep. considering that there is no approved maintenance manual for the 170A.
· That if the repair could be done in accordance with the AC 43.13 1b that a field approval would not be required as the AC could be used as Approved data listed in block 8 of a form 337. He read the purpose section of the AC to me. That as an IA I could sign this form off without a field approval.
· That if it could not be performed in accordance with the AC 43.1b the Data in it and in the 100 series maintenance manual could be used as supporting data for a field approval if no other data could documented. And that he would be happy to work with me on this issue. But… that in his opinion
· The repair I was performing did not fall into the scope and detail that was outlined in the 100 series maintenance manual and was fully covered in the AC 43.13-1b and required no field approval and as such by stating the proper chapter and verse of the AC in block 8 of the form I could fill out the form 337 complete and sign it off without any participation of the FAA in my project.
This all agrees with what I believe to be the case and is the process I have used in other repairs that I have performed in getting field approvals and filling out form 337,s for other aircraft that have no structural repair manual for the aircraft such as Mauls and various Piper aircraft.
In reference to comments in another thread elsewhere. These aircraft do have a maintenance manual in the form of the AC 43.13-1b the engine maintenance manual, the propeller maintenance manual and many other documents that can be used as supporting data for field approvals and filing of form 337’s, which would be required in any case with the repairs that I am completing.
This has always been my experiance in working with the FAA. I find them helpfull and I have no problem with them. There are however inspectors I avoid who do not have the experiance and understaning of their own documentation.

People will ask how I am maintaining alignment of the wing and other issues which are inumerable, but that is another story.