Trim

How to keep the Cessna 170 flying and airworthy.

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Mapleflt
Posts: 60
Joined: Sun Mar 05, 2017 3:20 pm

Trim

Post by Mapleflt »

I've heard tell of an electric rudder trim STC, can anyone substantiate this or is it just an urban myth
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Bruce Fenstermacher
Posts: 10313
Joined: Tue Apr 23, 2002 11:24 am

Re: Trim

Post by Bruce Fenstermacher »

Never heard of it though that doesn't mean it doesn't exist.

There was an STC from Aero-Trim for an electric trim servo and trim tab that could be added to just about any control in about any airplane according to the STC. I had one on my left aileron on my first 170. I became very familiar with it. Meet the STC owner at Sun N Fun once or twice. An interesting gentleman. His STC was granted in the "good old days" when there was more thumb nail engineering going on. Less paperwork.

When I meet the man he was an oddity from the start. First he was sitting on a high stool, between two booths with a parts tree and his STC product hanging from it. I think the parts tree was actually on one of the other vendors tables. As busy as Sun N Fun vendor building are, he was usually sleeping when I'd walk past. If someone woke him and showed interest in his product but wasn't ready to buy he'd lower his price. Ask for offers and then dicker a bit. When buyers would ask what needed to be done for approval he would ask if they were handy with tools. Tell them to install the servo, control, and tab, take pictures and send it to him, and he would approve it. My own aircraft records could attest to this as they included the picture signed and returned by him. All seemed reasonable to many. However a few years ago now the FAA caught on and they didn't think it so reasonable. I seem to recall he wasn't even a licensed mechanic though he was truly the owner and designer of the STC granted by the FAA, he couldn't install anything and certainly didn't have special power to approve anything via a picture. I'm fairly certain his STC was rescinded at the least.
IMG_0205.JPG
Wonder what I'll do with the spare system I bought from him in case mine ever needed replacement?
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
Mapleflt
Posts: 60
Joined: Sun Mar 05, 2017 3:20 pm

Re: Trim

Post by Mapleflt »

Are you "searching" for a repository for it !!!
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Bruce Fenstermacher
Posts: 10313
Joined: Tue Apr 23, 2002 11:24 am

Re: Trim

Post by Bruce Fenstermacher »

Mapleflt wrote:Are you "searching" for a repository for it !!!
No I wasn't as I wouldn't recommend it's installation. While I'm sure on some plane on some control surface it would be effective, on a 170B aileron, it was not.

I would give it up for someone who already had this system installed and was looking for parts otherwise it will remain in my pile of stuff I might need someday.
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
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c170b53
Posts: 2527
Joined: Mon Apr 22, 2002 8:01 pm

Re: Trim

Post by c170b53 »

Good one Bruce, that would be a good running topic, “what have you done for your parts stockpile today” or “ how big is your stockpile” , I’m sure we all have them.
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
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Joe Moilanen
Posts: 596
Joined: Sun Dec 28, 2003 5:45 am

Re: Trim

Post by Joe Moilanen »

Bruce Fenstermacher wrote:Never heard of it though that doesn't mean it doesn't exist.

There was an STC from Aero-Trim for an electric trim servo and trim tab that could be added to just about any control in about any airplane according to the STC. I had one on my left aileron on my first 170. I became very familiar with it. Meet the STC owner at Sun N Fun once or twice. An interesting gentleman. His STC was granted in the "good old days" when there was more thumb nail engineering going on. Less paperwork.

When I meet the man he was an oddity from the start. First he was sitting on a high stool, between two booths with a parts tree and his STC product hanging from it. I think the parts tree was actually on one of the other vendors tables. As busy as Sun N Fun vendor building are, he was usually sleeping when I'd walk past. If someone woke him and showed interest in his product but wasn't ready to buy he'd lower his price. Ask for offers and then dicker a bit. When buyers would ask what needed to be done for approval he would ask if they were handy with tools. Tell them to install the servo, control, and tab, take pictures and send it to him, and he would approve it. My own aircraft records could attest to this as they included the picture signed and returned by him. All seemed reasonable to many. However a few years ago now the FAA caught on and they didn't think it so reasonable. I seem to recall he wasn't even a licensed mechanic though he was truly the owner and designer of the STC granted by the FAA, he couldn't install anything and certainly didn't have special power to approve anything via a picture. I'm fairly certain his STC was rescinded at the least.
IMG_0205.JPG
Wonder what I'll do with the spare system I bought from him in case mine ever needed replacement?
Turned on the TV last night when I climbed into bed to watch a little something before I went to sleep. Surfing around for something to watch I noticed "Why Planes Crash" was on (could any of us look any farther for something to watch...) and they had an episode of a couple of 737's having full rudder deflection crashes. Evidently there was a hydraulic control valve issue where it would stick and the rudder input would be reversed. They both crashed before the pilots had a chance to figure it out. Hmmm....
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GAHorn
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Joined: Fri Apr 12, 2002 8:45 pm

Re: Trim

Post by GAHorn »

We had a (now deceased due to cancer) former Member who brought his airplane to the Branson convention and while touring the flight-line I noticed he had rivetted-on trim tabs on both ailerons. That is not a legal modification and I mention this to remind everyone of that.

If your airplane flies out-of-rig.... it needs to be rigged or repaired properly... it doesn't need an illegal band-aid. :wink:
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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