rudder control horn (rudder bellcrank)

simatos · Post by **simatos** » Mon Feb 21, 2005 6:13 pm

just installing rudder and I found on the control horn where the lower bearing fastens the lower hole is sized for #3 bolt but upper hole seems to be enlarged to about 1/2 inch and in fact the bolt heas falls thru and sits on the top of the bearing. The ips shows both the upper and lower hole to be the same Any ideas I am worried I am looking for a new control horn G

Walker · Post by **Walker** » Mon Feb 21, 2005 6:38 pm

Post by **GAHorn** » Mon Feb 21, 2005 9:18 pm

Are you referring to PN 0333119 ?? That bearing block includes/has installed a small bearing PN SAK-5 (Fafnir), which in turn includes a bushing. It is possible that you are describing a bearing block that has lost the Fafnir bearing. ??
(If so, I just also happen to have a new one as a spare.)

simatos · Post by **simatos** » Tue Feb 22, 2005 1:51 am

guys thanks George I know you encourage use to refer to part numbers from IPS. My ips is not handy just right now . Situation looks to me like upper portion of rudder horn has reamed itself against the mounting bolt and will need to be rebuilt. Another issue. Rigging flaps I have 2 ame at the field with 2 views One is saying that with flaps fully retracted roller bearings should contact firmly against forward end of guides otherwise there will always be some wiggle, while the other just adjusts push rod lengths to 7 7/17 in then tighten cables. doesn't it seem to make sense to have the flaps up to the maximum before tightening the cables?? Talk soon G

simatos · Post by **simatos** » Tue Feb 22, 2005 1:54 am

George me again I am just re-reading your note. The lower bearing support does have the bearing in place and looks ok. I will get the ips and get back to you exactly what part I mean Thanks again G

Post by **GAHorn** » Tue Feb 22, 2005 3:44 pm

simatos wrote:guys thanks George I know you encourage use to refer to part numbers from IPS. My ips is not handy just right now . Situation looks to me like upper portion of rudder horn has reamed itself against the mounting bolt and will need to be rebuilt. Another issue. Rigging flaps I have 2 ame at the field with 2 views One is saying that with flaps fully retracted roller bearings should contact firmly against forward end of guides otherwise there will always be some wiggle, while the other just adjusts push rod lengths to 7 7/17 in then tighten cables. doesn't it seem to make sense to have the flaps up to the maximum before tightening the cables?? Talk soon G

I suggest you re-post your flap question under a new heading. Otherwise we'll be talking FLAPS under RUDDER topic and things will get dis-cumbobulated.

Another member emailed me in his attempt to assist me to assist YOU. You're correct. Without the IPC we're all wasting time and efforts. I replied to his email thusly: "The problem is the lack of standard terminology. Explain to me what is meant by the term "rudder horn" and perhaps I can visualize what is being talked about. I see no part named "horn" in the IPC, and I see no AN3 bolt other than those which attach bearing blocks to the spar. (Traditionally, a "horn" of a flight control surface is the area containing a counterweight. IN the case of the 170. that is called a "tip" and there is no AN3 bolt associated with it as far as I know.)"

Walker · Post by **Walker** » Tue Feb 22, 2005 3:47 pm

Walker · Post by **Walker** » Tue Feb 22, 2005 3:54 pm

Post by **GAHorn** » Tue Feb 22, 2005 5:47 pm

This topic is an excellent example of how lack of use of IPC and proper terminology leads to confusion and wasted time. I've been informed by a member that the term "horn" is used by Piper to describe some bellcranks.

(The externally counterweigted flight controls of many British aircraft are so described as well, ala the Comanche rudder counterweights and the Staggerwing Beech lower elevator. I suppose this is due to their similarity in appearance to a cow's horns.)
In any case, the bellcrank (fig. 15, item 13) in question is not designed/intended to support the rudder. The two upper bearing blocks, figure 15, item 19 (two each) support the rudder and prevent wear of the lower hinge (fig. 25, item 25) and the associated bellcrank. If the AN3-10A bolt (not depicted anywhere I can find)

falls thru the upper surface of the bellcrank, it's because of a combination misalignment and/or mis-assembly and/or overtightening of that bolt due in part or perhaps in conjunction with missing parts such as the oilite bearing and bushing (fig. 25, items 26/27.) The AN3-10A bolt is only tightened to take up excess slack and is held by a AN365-1032 self-locking nut. If the bearing is missing, then overtightening of the AN3-10A bolt is possible thereby pulling it thru the upper surface of the bellcrank....or gravity will work with vibration to achieve the same defect (if that bushing is missing, or if the upper bearings are defective.) The bearing also serves to prevent crushing of the bellcrank.
The ONLY purpose of the lower hinge, oilite bearing, bushing, and AN3-10A bolt is to provide a pivot point for the rudder bellcrank against the constant pull of the rudder pedals/cables. There is no other provision for support of the rudder other than the upper bearing blocks.
The bellcrank, PN 0533000-30 is available from Cessna (PN 0433113) Spruce (their pn 05-07075, and Univair (pn U0433113). (All priced differently in the $210-$360 range.)
The original bearing PN A325-1 (superceded to S1003-11A) lists for $10.70 .
The bushing, PN 0431119 (List Price: $ 102.00).

simatos · Post by **simatos** » Sun Feb 27, 2005 7:34 pm

Fellows I have the IPC here and the issue is described on page 28 figure 15 at the bottom drawing of the bellcrank/rudder #0433113. On that drawing you can see the upper and lower mounting holes which attach the bellcrank to the hinge. My problem is this upper hole is worn away leaving a hole which is now over a half an inch wide. I think unless you are aware of some way around this I will have to change out the entire bellcrank. Dou you agree?? Sorry for the vague discription earlier. G

zero.one.victor · Post by **zero.one.victor** » Mon Feb 28, 2005 5:14 am

gahorn wrote:..... I've been informed by a member that the term "horn" is used by Piper to describe some bellcranks. ............

And the term "Horn" is used to describe some cranks! ( haha-sorry, couldn't resist!) )

Simatos, you might be able to drill out the oversized hole to where it's round, and then fabricate a bushing to size it back down to the size it should be. Don't know about the legality of such a fix.

Eric

jrenwick · Post by **jrenwick** » Mon Feb 28, 2005 6:35 am

zero.one.victor wrote:....... And the term "Horn" is used to describe some cranks! ( haha-sorry, couldn't resist!) )Eric

Damn, that's good. I wish I'd thought of it!

Apropos of that, on a long road trip today I was thinking about George's frequent assertions and how they sometimes draw fire from non-Texans (and maybe even from some of the Lone Star persuasion, I can't remember for sure). I'm grateful for his stewardship of this forum. I've learned a lot because of it. George has a wealth of knowledge and is not at all timid about sharing it. (Reminds me of the wag who said "You have a right to my opinion!") Seriously though -- we all gain when someone with a lot of knowledge and experience is willing to offer his expertise and opinions and take, with good humor, whatever comes. We all learn good stuff. I've even seen George learn from it!

Best Regards,

John

Post by **GAHorn** » Mon Feb 28, 2005 7:14 pm

I once was getting on a Delta flight to Philadelphia. I was going to rent a car to drive down to Wilmington to attend recurrent at FlightSafety on the Hawker.
When I got onboard the then-new 767, I noticed the flight crew's names were posted on the cockpit entry door, and the Captain was named "Don Horn" (which happens to be my Father's name also.) So I stuck my head in the cockpit and said "hi".
We had a nice conversation and Capt. Horn gave me the cooks-tour of the cockpit and began to describe the then-new system of laser-ring gyro equipment. It clearly became time to depart the gate and the Captain kept proudly telling me more and more about the features of the new airplane. The rest of the crew began to get a bit impatient and the Captain just kept on talking.
Finally it became noticeable that the First Officer was frantically and repeatedly/forcefully pressing a particular button on the instrument panel. Finally the F.O. blurted out....'I guess I'm going to have to write that up on the squawk-sheet!"
"Write what up?," asked Capt. Horn.
It then became apparent the F.O. had been frantically pressing the landing-gear-warning-silence button, placarded "Horn Silence".
The F.O. replied, "Well, it's pretty clear it doesn't work!"

simatos · Post by **simatos** » Thu Mar 10, 2005 4:50 am

Horn and/or bellcrank junk removed and replaced Thanks G