Rudder Trim Tab

[Dano"T"]

Okay...this sounds basic...but last night at the airport we were installing a rudder trim tab on my friends T-craft and we couldn't reach an agreement on which way the bend needs to go. The plane requires the pilot to hold right rudder to maintain straight flight so the argument was...does the trim tab get bent to the right as viewed from the back of the rudder to simulate the effects of right rudder pedal application? Or does the tab get bent to the left so that when the wind hits the tab it pushes the rudder over to the right? It was way too windy last night to test it out...so our debate rages on. Can anyone offer backup for me...we seem to have placed a little wager on the outcome.

Dan

[Richard Boyer]

Re: Rudder Trim Tab

I had to do this recently too. Just look at the elevator trim tab as a reference....of course I didn't think of that until I sat down for a few minutes and just stared at the rudder to set the tab. AFTER I set the tab I looked down at the evevator tab and just started laughing! The rudder tab will be bent towards the 'pilot' side of the aircraft which in turn pushes the rudder to the passenger side of the aircraft which in turn yaws the plane to the passenger side (to the right).

Richard Boyer
N95791
Georgetown, TX
(with a formerly tired right ankle from having to push the #$#$^%$#% rudder pedal all the @%$%$#^^ time.)

[mhorowit]

Re: Rudder Trim Tab

Interesting.
Same solution, different problem.
My problem was that my left wing was low so I had to hold right alerion.
My A&P added a rudder tab and we've been adjusting it to the pilot's side (port) to reduce the yaw. I'm close to being able to fly 'hands off'. should have it fixed by Alliance.

Yes, someone will chime in with wash-in/out, but let's try the easiest fixes first - Mike

[denny]

Re: Rudder Trim Tab

I was reading your stories about having to add trim tabs to fly straight and level. If I may recommend taking your trim tabs off and have an A&P use a calibrated cable tension gauge to set the proper tension on the flight controls.

You aircraft were designed to fly straight and level without trim tabs, if it doesn’t the rigging is off. I have rigged several of these aircraft and the first thing I noticed was the cables were old and stretched without the proper tension. With proper rigging you should fly straight and level.

Adding a trim tab is a major alteration and will require a FAA Form 337 and a flight test in accordance with part 91, this is a bandaid at best.

Denny

[NC36454]

Re: Rudder Trim Tab

Adding a trim tab is a major alteration and will require a FAA Form 337 and a flight test in accordance with part 91, this is a bandaid at best.

Denny

Denny,

Again, I must insist that you check facts before running some poor unsuspecting customer (someone giving money to an IA/A&P for helping process a 337) to the FAA. Page 10 of the Taylorcraft Service Manual clearly illustrates part "g"...a rudder trim tab. All Dano is doing is putting a factory part back on his plane that had probably been removed by a former owner.

The FARs define a "major alteration" as:

"Major alteration means an alteration not listed in the aircraft, aircraft engine, or propeller specifications—"

According to the aforementioned manual , Taylorcraft lists a rudder trim tab as a factory item.

As I've said before, we all spend enough money on these planes already without figuring out ways to spend even more!

If you feel a need to respond to this post, please do it with facts.

Thanks,
Ken
1941 BC12-65
W4SWK

[Don Eide]

Re: Rudder Trim Tab

Thanks Ken,

You beat me to the punch. I agree with you 100%.

Don

[alwaysoar]

Re: Rudder Trim Tab

Moreover, Denny, where do you get your figures for cable tension? Forrest always says cables should be kind of loose. So in addition to worrying someone needlessly about 337's etc, you are worrying him about cable tension needlessly. When I spoke with Forrest a long time ago about the rudder tab (mine was missing), he kindly emailed me a template and told me that if I poked around, I'd find the screw holes. I did, I did, and cut out a tab, and screwed it on--Voila

[mhorowit]

Re: Rudder Trim Tab

worrying someone needlessly

and I thought I was the designated person to worry needlessly about something!

[alwaysoar]

Re: Rudder Trim Tab

No, you're in a club. "Someone" worried needlessly, I always have a good reason.

[mhorowit]

Re: Rudder Trim Tab

We ought to coordinate.
Hate to see two folks worrying over the same item.
If you'll worry about improving cooling in the cockpit during hot days, I'll worry about lifting my left wing with the rudder trim; that way there won't be duplication of effort. - Mike

[alwaysoar]

Re: Rudder Trim Tab

I already worried about cooling in the cockpit and disconnected the heat duct. I am also going to install some plexiglass scoops on the windows until I get the time to make a sliding window. I also worried (a lot) about rigging until I jiggered around with the aft strut adjustment screws AND installed the aforementioned rudder tab. Now I have other worries

[NC36454]

Re: Rudder Trim Tab

Anyone care to volunteer to worry about my left mag...and brakes...and bungees...OH! and theres that sound I keep hearing every time I land...now that I think of it, I only hear that sound when I have a passenger...it's a sort of shrieking sound...hmmm


Ken

[alwaysoar]

Re: Rudder Trim Tab

I hear the shrieking sound when I'm solo--should I worry?

[mhorowit]

Re: Rudder Trim Tab

worry about ...and brakes...
Ken

What's the problem with the brakes?
I was having the dickens of a time getting the starboard one to work properly; everyone I talked to said "well those are Shinn brakes". Well, I lubed the pivot points for the horseshoe and insured both shoes were adjusted, and it made 1000% difference. Now I can pivot at the end of the runway to make sure no one is on final when I take the active. Everyone seems relieved. - Mike

[mhorowit]

Re: Rudder Trim Tab

I am also going to install some plexiglass scoops on the windows

Has anyone indicated there may be some added drag? What do these things look like? - Mike