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Modifying my super cub squared wing's tips

DGA has the idea. Granted, a lot of paperwork never gets looked at - we have really high power approved repair stations that routinely skip ADs on annual. One Mooney went for twenty years without fuel tank or control column AD compliance. Another doesn't do the Champ DMB wheel AD. And I mentioned the Cub muffler AD missed by three different shops (I insisted on an Atlee Dodge muffler - I hate doing that AD on a Super Cub).

So a fed says "minor" (by the way, modify a wing rib and it is not "minor"). Then change address and IA. On the minuscule chance that your new IA even spots it, you could be in for an expensive "un-modification!

I really like the less extreme wingtips, shown above. We do have a Super Cub here with those giant droops. Nobody likes them. Dakota makes reasonably good looking tips. I have no idea if modified tips do anything for a Cub. They usually hang them on after 200# of other kitschy mods, so performance is down from the get-go.

The statement by the fed was in reference to a cessna wing, with no modifications involved. Simply another shape at the tip. I do believe if you start cutting your Cub wing you will be doing something considered a major alteration and the requisite paperwork would need to be filed.
The comment about him calling it a "minor" was aimed at the idea of whether or not the particular shapes had much to do with adding performance.
Again, I don't know, and would love like the next person to find the magic bullet.. but it all seems to come down to weight.
A friend of mine commented that he wondered if the plane would slip as well without the original tips. That was food for thought for me and enough to decide to keep the nice round blend of original when I finally put mine together again.
Pure perfomance - my bet would be on the last rib covered with fabric.. but I really dunno and really don't care.. except for gaining knowledge.
One good reason to file a 337 is to have it for the time the "problem" FSDO guy shows up. Since there is no particular requirement to retain maintenance and minor alterations (other than transponder) records past a year, it's easy to have things not on the books. With a 337 you can show it was agreed to at a certain point in time. That's why I like to file them if I know they will be well-received by my PMI, because then it's on the record, whether needed or not.
 
that is no problem. Because one mans junk is anothers treasure. I think i said that the right way? were all individuals and if everything was done according to one mind this world would suck.

I agree when it comes to Fords vs Chevvies or blondes vs redheads.
Disagree when it comes to "the law"....
anything you can get approved by the Anchorage FSDO should also be approvable by the Seattle FSDO, and vice versa.
I know a guy who was building a Pacer with a lot of mods--
he didn't have paperwork or any other approval documentation for some of them.
He did talk to an IA who said he'd sign them off as minor alterations...
I told him to think long and hard about going that route,
he might be have trouble passing muster at annual time someday with a different IA who's more of a stickler..
 
I agree when it comes to Fords vs Chevvies or blondes vs redheads.
Disagree when it comes to "the law"....
anything you can get approved by the Anchorage FSDO should also be approvable by the Seattle FSDO, and vice versa.
I know a guy who was building a Pacer with a lot of mods--
he didn't have paperwork or any other approval documentation for some of them.
He did talk to an IA who said he'd sign them off as minor alterations...
I told him to think long and hard about going that route,
he might be have trouble passing muster at annual time someday with a different IA who's more of a stickler..

I always tell someone that is planning on making a “minor alteration” determination to follow that up with the decision logic from AC43-210A figure 3-1. If you use the FAAs own guidance, answer the questions truthfully, and document it in the maintenance records, even if someone in the future disagrees, you have documentation to support your decisions. The real question with wing changes (even just tips) how do you support no change to performance or flight characteristics without flight testing? Isn’t the original idea of changing tip to change performance?


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My old PMI always used to tell me that he never heard of anyone getting in trouble for filing a 337....but he'd seen a few that did for not filing one.
John
 
Just filing a 337 doesn't do it. For a major alteration (a wingtip, for instance) you need either a field approval with an FAA stamp in block 3, or an STC, or something that has been determined to be "approved data" for the installer.

I am with Web on the lights. That's what I did. I figure a lightbulb change barely needs a logbook entry. Barely. (I hate cluttered logbooks; my oil changes go on the hangar wall, to be erased in a year).
 
You can pretty much erase everything but AD compliance, transponder checks, time-life components (any on a Cub?), and major repairs/alterations within a year if you don't like cluttered logs.
One AMD inspector suggested I keep a "needed" set of records, and an "archive" set of records. Makes it easier for the inspectors to glean the relevant information, but still allows you to keep a history of your plane. That history is not required by regulation but is desirable for most. I don't like incomplete logs but aside from the aforementioned (unless I forgot one) they are not required.
 
.... That history is not required by regulation but is desirable for most. ....

Yes. Take note of how many "complete logs back to new" are included in for sale ads.
I know some people don't even log things like oil changes,
but as a buyer it's nice to look and see that the oil was changed every 25 or 30 or whatever hours.
Ditto in the case of a loose engine that (as per another thread) it has been regularly inspected as appropriate.
 
My old PMI always used to tell me that he never heard of anyone getting in trouble for filing a 337....but he'd seen a few that did for not filing one.
John

Funny thing here, while I’ve never heard of anyone being violated for it, filing a 337 for a minor alteration or a minor repair is a violation of 43.9.

As a DER, the guidance we have says we can’t provide “approved data” for minor repairs or minor alterations. That’s a sure way to become a former DER.


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When I first got my IA, I filed with the FSDO a 337 for a new instrument panel and vacuum system. I never heard back.

Then (as with most things) I learned on the job about how complicated and abstruse the 337 was, and decided my instrument panel was a minor mod. I should check to see if they sent it to OKC. I bet they just filed it.

Logbooks with entries for every flight make an IA's life miserable. I figure two pages per year is a reasonable average for an aircraft not engaged in commercial activity, and oil and tire changes go on the wall. I don't care whether a purchaser wants oil change records - I will be gone then.

I don't do miscellaneous annuals - liability insurance starts at $4 grand a year - but if I did, I would want to spot initial entries for all mods, major repairs, and ADs. The 337s would be good enough for majors, but I personally would want to verify the original entry for ADs (unless recurrent, of course). Those become difficult to spot in cluttered logbooks, and mechanic time hereabouts just topped $115/hour. If you have cluttered logs, flag these things!

Opinion, of course.
 
Funny thing here, while I’ve never heard of anyone being violated for it, filing a 337 for a minor alteration or a minor repair is a violation of 43.9.

As a DER, the guidance we have says we can’t provide “approved data” for minor repairs or minor alterations. That’s a sure way to become a former DER.


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What he was trying to say is that if you determine that it was a minor, and it turns out that it's a major, you're gonna wish you'd sent the 337 in and had your PMI explain to you why it was a minor. Maybe I'm different, but if I think it's a major (and I don't have an STC, etc.), I send in my 337 BEFORE I do the work. More than once, I've had my PMI determine that they thought it was a minor according to their guidance.
John
 
What he was trying to say is that if you determine that it was a minor, and it turns out that it's a major, you're gonna wish you'd sent the 337 in and had your PMI explain to you why it was a minor. Maybe I'm different, but if I think it's a major (and I don't have an STC, etc.), I send in my 337 BEFORE I do the work. More than once, I've had my PMI determine that they thought it was a minor according to their guidance.
John

Actually what I was saying is that if you use the guidance FAA provides to determine it is a minor, and document your decision logic, FAA could never make a violation stick if they chose to try an enforcement action.


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new lightweight carbon fiber wingtips

wingtip 5.jpgWhite Wings Aircraft Services at Lake Hood is doing my lightweight Husky project. Had some molds made for lightweight wingtips of carbon fiber. The Husky and cub airfoil is the same, so wingtips work on either one.
They weigh 2 lbs each. Think they are pretty much like the Dakota style.
Attached are some pictures. Have not flown them yet on Husky. They are top quality.
Starr Farmer at White Wings Aircraft can supply the set for $650.
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He’s worked on my Cessna for many years. I enjoy that relationship. Anderson is an asset, too.

When’s the Husky first flight? There isn’t much left to do.
 
He’s worked on my Cessna for many years. I enjoy that relationship. Anderson is an asset, too.

When’s the Husky first flight? There isn’t much left to do.

Stewart,
Nice that Anderson is now an A & P at age 20, pretty cool to have grandson in the mix. The big thing now on Husky is the weigh in, hoping for well under 1200lbs, but the proof is all together first, with cargo pod to see what it really weighs. Maybe another couple weeks yet. Lots of little details. You know how it goes, 90% finished and 25% yet to go!!!
John
 
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