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OK....I know this topic has been discussed many a time, and I've read through the many postings, so I'm hoping for a few comments to clarify things as they might currently stand.
N43319 (serial #6978) currently has an A75 hung on her with a field approval. Well and good...she's doing OK but a little tired.
In my parts collection I have a C85-12 in pieces....everything looks pretty good, even a new cam, but without the fuel pump lobe. Thought I had a prop too but it turned out to be a McCauley 1A105 7155 fresh from the shop (anybody need that one for something, by the way? swap? hint hint).
So, I can potentially go to an 85 for minimal cash, which is very good. What I want to do, hopefully, is go with the -12 with covers on the back, no electrical, on my short mount....the prop I can sort out later. I don't have a problem leaving the gross at 1200 if I can do the FWF without structural mods, if I have to make the mods I'd bump it to 1280.
Looking for a little guidance relative to paperwork and the likelihood of approvals. I know a simple field approval likely isn't in the cards anymore. I know about the SA1-201 STC and understand what is involved. I know that if someone has a 337 from before 1955 I might be able to use that as hard data for a "simple" FWF swap approval on a BC with a number earlier than 12000.
In the technical part of the forum I found the approval, dated 1974, that Wipline used on N43168 (serial #6827) to do exactly what I want to do utilizing only the fuel system mods of SA1-201 and omitting the wing mods, leaving the gross at 1200. If I approach the FSDO (hoping someone is in a good mood) with a copy of that 337 and the cover letters from the engineering and manufacturing branch, how does the tribe feel my chances of success might be? Should I try to find an additional example too (anybody have one handy?). My fuel system is already 3/8", and I have tanks in both wings, so leaving the gross at 1200 and not doing the wing mods would make this a relatively easy endeavor.
If I have to, I will do the mods...planning on it down the road just not in the cards right now, hopefully. Have a set of wings that were going to go on a BC12D to F-19 project. One is almost ready for cover with the modified strut attachments already on, the other is half way there. I will eventually be putting the new wings on anyway, but that's going to be in the future. So, the way I understand it, if I could get approval do what Wipline did in 1974 using part of the STC for now, I could go ahead and incorporate the mods with the new wings later on and bump my gross then. Pretty easy to do it that way, and I'd get the power boost now. Trying to get as many ducks in a row before starting any serious, committed efforts.
Sorry for the long post...hopefully it's clear enough. Would appreciate any comments good or bad from folks with more experience on this. Thanks much.
N43319 (serial #6978) currently has an A75 hung on her with a field approval. Well and good...she's doing OK but a little tired.
In my parts collection I have a C85-12 in pieces....everything looks pretty good, even a new cam, but without the fuel pump lobe. Thought I had a prop too but it turned out to be a McCauley 1A105 7155 fresh from the shop (anybody need that one for something, by the way? swap? hint hint).
So, I can potentially go to an 85 for minimal cash, which is very good. What I want to do, hopefully, is go with the -12 with covers on the back, no electrical, on my short mount....the prop I can sort out later. I don't have a problem leaving the gross at 1200 if I can do the FWF without structural mods, if I have to make the mods I'd bump it to 1280.
Looking for a little guidance relative to paperwork and the likelihood of approvals. I know a simple field approval likely isn't in the cards anymore. I know about the SA1-201 STC and understand what is involved. I know that if someone has a 337 from before 1955 I might be able to use that as hard data for a "simple" FWF swap approval on a BC with a number earlier than 12000.
In the technical part of the forum I found the approval, dated 1974, that Wipline used on N43168 (serial #6827) to do exactly what I want to do utilizing only the fuel system mods of SA1-201 and omitting the wing mods, leaving the gross at 1200. If I approach the FSDO (hoping someone is in a good mood) with a copy of that 337 and the cover letters from the engineering and manufacturing branch, how does the tribe feel my chances of success might be? Should I try to find an additional example too (anybody have one handy?). My fuel system is already 3/8", and I have tanks in both wings, so leaving the gross at 1200 and not doing the wing mods would make this a relatively easy endeavor.
If I have to, I will do the mods...planning on it down the road just not in the cards right now, hopefully. Have a set of wings that were going to go on a BC12D to F-19 project. One is almost ready for cover with the modified strut attachments already on, the other is half way there. I will eventually be putting the new wings on anyway, but that's going to be in the future. So, the way I understand it, if I could get approval do what Wipline did in 1974 using part of the STC for now, I could go ahead and incorporate the mods with the new wings later on and bump my gross then. Pretty easy to do it that way, and I'd get the power boost now. Trying to get as many ducks in a row before starting any serious, committed efforts.
Sorry for the long post...hopefully it's clear enough. Would appreciate any comments good or bad from folks with more experience on this. Thanks much.
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