To answer your question, the first word in note 3 of the TCDS is MANDATORY. So I would think the inspection is mandatory. Under section 12 Airworthiness Limitations in my service manual it details the inspection. Looks like a fluorescent dye penetrant inspection is required paying close attention to the bores of each hole. It references SL 414 or 415.
Just because someone had put the word MANDATORY in the title does not make it mandatory.... Continental (and every other manufacturer) issues Service Bulletins and MANDATORY Service Bulletins (even colored in RED).... Neither of which are MANDATORY for part 91.
Now, hold the stones, I'm not saying we shouldn't, just pointing out, it's not required for airworthiness. I personally comply with all mandatory SBs, and at least read regular SBs to see if it's reasonable. I have found that most Mandatory SBs become ADs eventually, at which point, they become MANDATORY for airworthiness.
A FAA legal interpretation states that you do NOT need the latest revision of the manual. You just need the revision that was current when that particular aircraft was manufactured.... Again, just talking part 91. So, the Owner provided Service Manual would be legal to use.
Maintenance manuals and ICAs are not "FAA Approved", just "Acceptable to the Administrator", therefore not required to be followed. However, if they have the "FAA Approved" Airworthiness Limitations section then yes, MANDATORY. Most ICAs do not. I'm not saying that this particular inspection is not a "FAA Approved Airworthiness Limitation" inspection in the manual. I just don't know that. The newest champ aircraft I have worked on was a 1980 Scout. I just haven't had the opportunity to see a newer ACA manual.
Let’s assume that there is/was NO “FAA Approved Airworthiness Limitation” section in the service manual and ICA…. Does putting it in a note in the TC now make it MANDATORY? That is the question I will bring up with my PMI. This is the first instance that I have seen/heard of any type of inspection interval requirement in a TC.
So, seems easy-ish for any ACA manufactured plane. My question is, how does ACA handle a retrofit bird? I have yet to experience that either.
For those with an older Citabria or Bellanca that had factory new wings installed, what were you handed? A new service manual? Or an ICA with the the "FAA Approved Airworthiness Limitation" section?
If its a Service Manual; Am I required to maintain the wings to 2025 limitations, but continue to maintain the rest of the plane to 1969? Or does the rest of the plane now get rolled into any new airworthiness limitations?
Sure is making it harder everyday to want to maintain my IA!
And last question, what other “Airworthiness Limitations” are in this Section 12 for ACA?