Bill, Good question given today's tightning approach to "acceptable data" for a 337. The 337 for the O200 install is very short on information or back-up/supporting data. It would almost certainly not be accepted by your local FSDO today. Of course if an IA signed it off the copy, today, is sent directly to the OK City files so the local FSDO dosen't look at it... but if they had a reason to look (not too likely but still possible), the IA (and you) would almost certainly be paid a visit. I predict that this 'noose' is just going to continue to tighten up as time goes on.
The rather time honored 'piggy-back' 337 aproach is a real gray area. My copy of FAA-G-8082-19 (IA Information Guide) lists 19 items as possible forms of approved data. The only 337 related ones are: #5. "...337 whici has been used for multiple identical aircraft (only by the original modifier)." and #6. "...(any) 337 dated before Oct.1, 1955." Today it is VERY DIFFICULT to get the local inspectors out to do a field approval of a 337. They will recomend that you get an approved engineer (DER) to approve your data which seems to be their desired method. Last time I used a DER his fee was $500.
See next post...