SB1379 - Rudder Inspection

Tagged to watch...

I don't (yet) know how to do fabric work, so sliding a tube down the rudder spar sounds a whole lot better to me at this point.

How would I inspect for this failure? My 1953 22-135 converted to a taildragger and o-320 has not had a beacon on it since I have owned it, but the rudder spar has threads on it, so I would guess that at one point it did. Will I need a borescope, or will I be able to see/feel cracks from the outside through the fabric?
 
Without taking the fabric off you won't. Push the rudder counterbalance above the top hinge left and right and see if it gives.
 
My rudder post is likewise threaded on top and previously had a beacon installed, but subsequently removed prior to my ownership. The service bulletin says all PA 22s are affected.

The SB says to confirm you have a rudder made with 4130 normalized.

I like Rocket’s idea of installing a 4130 doubler. Partial length, or full length?

Do you believe that installing a full length 4130 sleeve could be considered as complying with the service bulletin? What wall thickness would you use for the three-quarter inch diameter tube?

And would someone please restate/confirm what structural adhesive should be used to bond in the Doubler? Thanks.
 
Last edited:
As the rudder is a flight control, repairs or modifications need to be taken seriously. Sleeving the rudder post would probably be considered a major repair or modification. This would require approved data for a form 337, probably from a DER. And, only the installation of a rudder manufactured from 4130 steel would comply with the SB. It would likely be more cost effective to just purchase a new rudder manufactured of the required material or make an “owner supplied” part than try to get the modification approved. I do not believe that you could drive a repair sleeve up from the bottom without damage and coming down from the top would also require opening up the rudder. How you would ensure that the adhesive remained where it was supposed to? If I was even contemplating a sleeve type repair, I would remove the fabric and check for pitting and/or cracks. If all was pristine, I would sleeve the rudder post and secure the repair sleeve with rosset welds. I would then epoxy prime inside and out before I recovered the rudder with fabric. It would not comply with the SB but I would know that it should never have an issue at that hinge line attachment.
Merry Christmas to all!
N2709P
 
…It would likely be more cost effective to just purchase a new rudder manufactured of the required material or make an “owner supplied” part than try to get the modification approved.
Merry Christmas to all!
N2709P
Yep, I think you put your finger right on it. Merry Christmas!
 
I don't have AC43.13 in front of me but repair by sleeve method is called out there. It has been proven that the 3/4" x .035" wall tube will slide in from the bottom after cleaning some of the weld burn through from around the steering arm. The tailwheel airplanes have 2 holes drilled to hold the tail wheel steering arm and the Tri-Pacer has a hole drilled for the tail skid so I see no need for epoxy. I don't care about complying with the service bulletin as I am not flying part 135. Looks like to me I would need to revise weight and balance maybe and make a logbook entry. All that said I am not real concerned with this issue of my rudder failing or the FAA issuing an Airworthiness Directive. Been a long time and no Notice of Proposed Rule Making.
 
I have to agree with Steve. A lot of “mandatory” SBs are issued that never turn into ADs. Truth be told, I think SB319 would be better to make an AD than this one. I’ve seen a lot more damage around the door frames than in the rudder.

Doing an internal sleeve repair already has approved data in AC43.13-1b Chapter 4, so no real need to look further than that. Given the stress concentration just above the upper hinge, the sleeve would only need to extend maybe 4” below the hinge and maybe halfway from the hinge to the top of the rudder. Not much weight, and not far from the hinge line so no real aerodynamic impact from a flutter standpoint.

Our airframes are getting older and we all need to do better when inspecting them.


Sent from my iPad using Tapatalk
 
Piper issued a revision in Service Bulletin 1379A today. In reviewing it not much has changed. Still nothing out of the FAA. I think this is gonna be a hard one for them to justify.
 
Piper issued a revision in Service Bulletin 1379A today. In reviewing it not much has changed. Still nothing out of the FAA. I think this is gonna be a hard one for them to justify.

Doesn't the new revision narrow the serial numbers for the PA-22 down to PA22-1 through PA22-532? So, only the first 532 PA-22s are affected?

Juergen
Pacer N3342Z
 
That is huge considering there were like 8,000 22s built. Takes my 22 #7325 out of it but leaves my 20. Wonder what was different for the 532.
 
I will bet they made a mistake. Rudders didn't change till 1975 when they started making them out of 4130. My Super Cub is now listed and I know it has a 4130 ruder from the factory. I see revision B coming out soon. Can't imagine an AD is going to come out this late in the game.
 
...and the Tri-Pacer has a hole drilled for the tail skid so I see no need for epoxy...

Steve, I believe the PA22 tail skid is mounted to the unmoving, trailing edge tubing of the fin/fuselage, not the moving part of the rudder that is the concern of the SB, correct?

I recall reading that when doing the tailwheel conversion on a PA22, a reinforcement sleeve is installed inside that rear tubing of the fuselage, fixed with rosette welds in the former tailskid bolt-holes, so there is precedent for such a reinforcement sleeve in the rudder post.
And a cherry rivet to retain the sleeve in the rudder post should be quite adequate to keep it from slipping out.

GG
 
I thought I had posted this here a while back but could not find it:


So I experimented with two rudders this morning. One was an old Univair 4130 rudder which was TIG welded when manufactured and the other was an original mid 50s rudder of a Pacer which would have been oxy/acetylene welded . I used a piece of 3/4" OD x .049" wall 4130 tubing as a sleeve. It slid right into the 4130 TIG welded rudder. On the old Pacer rudder I shot some Corrosion X inside the rudder tube and some grease on the 4130 liner tub and lightly taped the tube in all the way to the top of the rudder as my daughter held the rudder. Nice and tight and I can remove it if I needed to. I don't see the two tubes working inside one another and wearing like I was told by an engineer that wanted to see rosette welds to make the two tubes one.


Per my conversation with folks at AOPA today I am seeking ideas for an AMOC (alternate means of compliance) if and when the NPRM (notice of proposed rulemaking) comes out for an AD on this.

I have also requested the accident/incident reports on the 12 rudder cracks that the FAA has identified to see if these were all 1025 steel rudders and if all had rotating beacons installed.



 
Steve, as long as it’s been since the first report I doubt FAA is actually working on an AD. Look how long SB 819 has been around for corrosion on the fuselage yet no AD. It would probably be a good idea for the Short Wing Piper Club and if the Cub Club is still around (or any other type club that represents tube & fabric Pipers) to actually have a meeting with the Atlanta ACO to see if there is any activity on this. Better to head it off before an NPRM as once that’s published there can’t be sny Ex parte communications except the comments to the NPRM.


Sent from my iPhone using Tapatalk
 
We just purchased a Colt and have been watching this proposed AD. It looks like Univair has rudders made of 4130. Would the ones they sell comply with the AD out of the box then?
 
At least we have 5 years to comply. Hopefully we will develop an alternative Methode of compliance by then.

Juergen
Pacer N3342Z
 
At least we have 5 years to comply. Hopefully we will develop an alternative Methode of compliance by then.

Juergen
Pacer N3342Z

I read it as 3 years for mine:
150hp, no rudder beacon ( ie cat II )

Bryan


Sent from my iPhone using Tapatalk
 
I read it as 5 years for mine 150hp no rudder mount for beacon, cat III

You are cat II:

Category II Airplanes: Airplanes having either a rudder post mounted beacon light or a 150 or greater HP engine installed

Key word is OR
Beacon mount OR 150 HP or more.


Sent from my iPhone using Tapatalk
 
Mine is a 108 Colt with tail post extension for light. It looks like three years for compliance. Can anyone explain what the actual compliance is for the rudder?
 
Mine is a 108 Colt with tail post extension for light. It looks like three years for compliance. Can anyone explain what the actual compliance is for the rudder?

Rudder post doesn’t matter unless it has a beacon mounted on it. You should be category III.


Sent from my iPad using Tapatalk
 
Back
Top