How to fix a bent rudder horn

[akndrifter]

The old maule tailwheel broke on me in December, and it finally melted out enough for me to get the rudder off last week. The part that got beat up worst was the rudder horn, what is the best way to fix it/bend it back?

[Pearson]

Re: How to fix a bent rudder horn

It depends on how far it was bent, and in which direction. To a certain degree, anytime you bend metal you are weakening it. If it didn't bend too far, it probably didn't weaken it a whole lot. Also, if it was bent up or down, it may still be strong enough as far as fore and aft. Someone that understands metal structure needs to take a close look at it. It may be possible to heat it mildly, restraighten it, and then have it heat treated. But like I mentioned, someone with some knowledge of metal needs to take a close look. If it is bent very much, you MAY need to chunk it and find another one. If you need it, there is a metalurgist at Stack Metalurgical & Heat Treating in Portland, OR. Send it to him and he can tell you for sure, if it is salvageable.

[akndrifter]

Re: How to fix a bent rudder horn

I don't think it was bent fore and aft. But if it is junk now, does anyone even make these any more?

[Joel Severinghaus]

Re: How to fix a bent rudder horn

I need to replace a rudder horn too. The holes at the end of my rudder arm are elongated, because they were never protected with bushings. They're now elongated enough that the steering springs can pop out, even though moused with safety wire. (I have a runway light groundloop trophy to prove it, too.)

The factory "Alighting Gear Installation" drawing #0866 shows a part number B-9137 Rudder Arm (Heath Co. #42-RA-200).

Aircraft Spruce sells rudder arms with either 3/4" or 1" diameter shanks/posts:
3/4": p/n 06-15900
1": p/n 06-01045

Ditto for Wag-Aero:
3/4": p/n D-211-001
1": p/n D-211-000

These are all $36-38.

I seem to remember a thread a while back about maybe the 3/4" diameter replacement arms being too large for the Taylorcraft rudder tube, and needing to turn them down on a lathe? (Sorry, searched for that thread but couldn't find it.)

Is the 3/4" diameter shank the correct size, and are these shanks long enough to drill the three bolt holes? Anybody have experience with them?

[MNJoe]

Re: How to fix a bent rudder horn

I bought (two just in case) don't remember which one and had it turned down in a lathe to fit my rudder, my rudder arm was to far bent after a ground loop and $9000.00

[Joel Severinghaus]

Re: How to fix a bent rudder horn

Well, nuts.

A new Wag-Aero rudder arm turned out to be too short. Not only was the vertical shaft too large a diameter for the rudder tube, but it was only long enough for two of the three bolts that secure the rudder arm inside the rudder tube.

So my shop ended up sending out my 64-year-old original rudder arm to have new material brazed into the elongated steering spring holes, then re-drilled. Looks like they should last another 64 years now...

[astjp2]

Re: How to fix a bent rudder horn

The taylorcraft ones are steel and most of the replacements I have seen are aluminum. I would heat and bend back straight. Tim