185 gearlegs on a 170B

[GAHorn]

Why do we have to pay $145 for a cargas STC for our 170's to make cargas use legal? The airplane doesn't know if I have the paperwork or not. Same kind of deal.

Eric

I know that YOU know this, Eric, but just to keep things in perspective: There are two reasons to pay for any STC. 1- You don't have to go to all the expense of engineering data acquisition, extensive testing (and subjecting your airplane to that testing, or pay for all the fuel and aircraft engine time to perform those tests) and liabilities without insurance while your airplane is on an experimental certificate and; 2- you are assured of getting all the necessary operating information to use the modification safely (whether or not you actually perform the necessary precautions, ...with the STC purchase at least you are assured of having the data available to you.) Without an STC, you are merely riding along in an experiment with your own airplane, whether or not the modification has been performed on other airplanes seemingly identical.
The legal option available to you otherwise is to submit for a "field approval", which I dare say for most owners will likely end up costing the same $145 for all the time, trouble, and Form 337 submission fees from an IA. (I know, I know, ...the counter-argument is that the IA will spend the same amount of time filling out the STC paperwork as he will a 337-field approval, but that is not correct. Try it. If you have an IA apply for field approval, he will have to submit either approved data (from an existing engineering study...which will cost you) or acceptable data (from an airplane already approved for the identical mod. This is not possible since field approvals have not been made for autogas useage....only STC's....which means you'd be copying an STC and then the FAA will deny the field approval because it is essentially copying an existing STC that you should be purchasing, a-la patent infringement.)
And that's why not only is it fair to pay an STC holder for his work product and his liability exposure, but also it's usually the less expensive route to go anyway.

[28Charlie]

I called these folks and was quoted $200 for the stc.
Quote from a previous post.
STC SA00173BO allows installation of 180 gears 0741001-1,2,3,4,5, and 6 on all 170B's. It is not a one time STC. Owner of the STC is Aero, LLC 1095 Silver Mills Road, Sangerville, Maine 04479 . 207 924 5905. Aero, LLC also holds STC SA00189BO wich allows installation of the heavy duty steel axles (1441003-1) on the 170B and 170-A ( serial 19219 and higher). The steel axles are much stronger than the solid aluminum axle 0541124-1.

[zero.one.victor]

You don't have to buy the STC, just install them & go for a field approval like you been doing. Maybe they'll OK it,maybe not,maybe they'll want you to develop an approved STC of your own,or get one from someone else.
Eric Leclercq coresponded with me quite a bit while he was jumping thru all the hoops required by Transport Canada (their version of the FAA) to obtain a multiple-use STC. I guess he did it all again (or concurrently) with the FAA also. I took quite a few measurements off my ragwing,which he needed to get that STC. $300 CDN (probably around $225 US at the current exchange rate) seems like a lot,doesn't it? Stop and think about all the work that went into getting the STC. If he sells a thousand,he'll be rolling in dough. What if he only sells 2? Not much of a payback.
I think that buying Eric L's STC may be a pretty good bargain if you get out of going thru all the field approval BS with your local FSDO. They might ask for engineering data,flight/taxi testing,etc.-- a simple "we've been doing it for years" may not cut it with them. And if yours is one of those "we don't do field approvals" FSDO's, it may be the deal of the century!

Eric

George,you missed my whole point. Read the above post,which I wrote about 12 hours before the one you quoted,and you'll see that my question about "why do we need the cargas STC" is somewhat rhetorical. I think we're saying pretty much the same thing here.

Eric

[GAHorn]

I neither missed your point nor thought your subsequent post "rhetorical" and to keep my comment in context is why I quoted you. (I did/do recognize you probably know better, so I mentioned that.) I thought your subsequent post brought up a fine point that might be helpful to others if addressed.
Another instance: The comment you offer when quoting yourself: "You don't have to buy the STC, just install them & go for a field approval like you been doing. ..." ... is exactly NOT the way to "go for a field approval" unless you like developing a controversy with the FAA inspector.
Any FAA inspector who signs off on your request for a field approval is putting his job, reputation, and liability on the line. Considering that, why do you suppose so many of them get "horsey" when confronted with an owner who's already made some modification and THEN contacted them asking for approval? It's fairly presumptious to assume one can perform a "common" modification, and yet ask an inspector to put his job and reputation on the line without first consulting him.
Any time one plans to ask an inspector to approve something one wishes to do to one's airplane, it's not only best to gain tacit approval BEFORE the work is actually performed,... it's also frugal,... (not to mention courteous.)