Here is what the FAA web site has to say. As Ruidoso Ron said, 135 hp is the minimum for this STC.
Darrel
I think 135 hp is the minimum but only with a PA-18-135. A PA-18-105 upgraded to an o-290 would not count. It would only be valid if it was a PA-18-105 with an o320 installed.
Is that correct?
Give his daughter Karen a call. She can read the STC to you and would be happy to sell it as well.
https://fadodge.com/faqs/
I think there are few supercubs out there that are completely legal. And many off them are not that way purposely, as different people interpret written things very differently. STC's get partially completed or slightly modified by the owner or installer which in many cases makes the machine technically un-airworthy. And then there are those (mostly individual owners) who just don't care and will do whatever they want to get the plane the way they want it. They should be flying experimentals. Many go un-noticed for decades and may never be an issue unless there is an incident that involves the feds. Then it may be just a grounding of the machine and a slap on the wrist (or worse). Most of us who build and rebuild cubs for customers do our best to keep things legal because it is in our best interest to do so. I think today insurance companies are where the major problems arise. And they can frequently find reasons not to pay. There is a lot of material out there today that is better than Piper original equipment. It's too bad more of it can't be used in modernizing these old machines but the fed machine is just too big for us to battle on our budget. Just my 2 cents.
I think most of us who are involved with the mechanical aspect of flying are aware of field approvals-- form 8110-3's, maybe not so much.
I never knew about them until about 7 years ago when I found one, looking through the paperwork of an airplane I'd bought.
I'm curious as to what kind of fees DAR's charge?
For example, I got a field approval a couple years ago for 26" Goodyears on my 180.
BTW this is a pretty common mod, I was pretty surprised to find that no one seems to hold an STC for it.
I gathered up copies of a number of previously approved 337's for other airplanes to support my 337 application,
I finally got it approved through the local FSDO but it took 11 months, and several phone calls & emails prodding the inspector along. Very frustrating.
What would you yourself charge for doing an 8110-3 for this installation, and what sort of documentation would you need?
As for paperwork errors and Cubs -
Most weight and balance forms have errors. Often that works in a favorable way, since re-computing can often convert a Cub back to 2 place. Cubs all have two different datums, driving mechanics into serious balance errors.
About half the major alteration 337s I see cite no "approved data" - in some cases the IA assumes he can simply sign it. In about half the fuel tank 337s, the IA cites an STC for a different model aircraft. I own two aircraft like that, and in the first week of ownership I got field approvals.
One stunningly beautiful Cub had a truly inaccurate fuel tank 337 - two different wing tanks, no nose tank, incorrect quantities in paperwork and markings - yow! That day I got five field approvals signed!
Shhh! I could get revocations going all the way back to the 1980s. Found a C-90-12 installed on a J3 in 1985, with IA approval. The aircraft since then was annualled over 30 times, mostly by approved repair shops, and meticulously restored in the early 'oughts.
One of my Cubs sailed through a restoration and 20 annuals with an unapproved wing tank.
A while ago a Mooney made it through 20 years of annuals by an FAA repair shop/Mooney dealership without even pencil whipping two major ADs.
If anybody looks too hard we are all going to jail!
What are you wanting to do? They only way to up the gross weight that I am aware of is with the O-320 on any of the STCs and the additional tubes, balanced tail, cabane bolts etc.I think 135 hp is the minimum but only with a PA-18-135. A PA-18-105 upgraded to an o-290 would not count. It would only be valid if it was a PA-18-105 with an o320 installed.
Is that correct?
I think his question is this: if an STC is specifically restricted to Cubs with 150 hp engines and makes an express exception for the PA-18-135, can you convert a 105 Special to 135 configuration (it is still a 105 Special, right?) and use the restrictive STC?
My question would be can you just use the type certificate, add all those tubes, and convert to 1750 gross? I think I have seen several 150/160 cubs that were originally 18-95s.
I may have hijacked the thread with that one. I am talking about a different plane than the original poster. Perhaps I should start a new thread?Where exactly does it say "135", "125," "105" etc? All I see is "PA-18" on rego and data plate.
This plane came from factory with 0235 but also with flaps- so it's not a -105 and not a 105 special I don't think because factory heel brakes as well.
TC says almost all serial numbers can be any model except for -150's.
Seems this plane isn't any of the types listed.
I read another thread hear about these planes- apparently they were called "patrol cubs."
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