Does anyone have a Aussie Horn installation instructions. I’m trying to determine how difficult it would be to do myself and if any special tooling is required.

@john-armstrong Send it to Heritage Aero... you have about 15 seconds to match the two parts after you get one to a suitable high heat and the other to a suitable cold temperature to get a perfect alignment... after that you are screwed.

Jim

John:

I have those instructions and have performed this task.  It is pretty simple to describe though:

1)  Disassemble the tail of the aircraft completely from the elevator cables back.  Basic hand tools will do.

2)  Remove the old horn from the balance arm with a careful application of heat and force.

3)  Carefully measure the new horn inside and out with calipers to ensure the steel balance arm will fit properly with respect to depth and that the alignment holes will in fact align.  You will need accurate calipers for this.  Dress the end of the balance arm properly with a file if required.  

4)  You will need various loktite-style chemicals for preparing and securing the various heat shrunk surfaces per the instructions.  Remove all burrs, clean, and prepare the surfaces.

5)  You will need to heat the horn to about 400 degrees in an oven and then quickly and smoothly place it on the steel balance arm.  You have one chance to get this right.  Practice with the old horn a few times.  You will need to slide it over the steel balance arm and align it with a tapered pin.  A special alignment pin is needed.

6)  You will need to place alignment bushings inside the torque tube, slide the horn into position, and ream out the horn so it exactly matches the existing holes.  You will need a pilot reamer that fits the alignment bushings.  Clean and deburr all holes / surfaces.

7)  Put everything back together, while preparing all surfaces with the various locktite chemicals.  Torque it all down.  You will need a calibrated torque wrench that can be set in inch-pounds.

8)  Paint everything properly.  You will need the paint.  You could argue this point but the instructions require it.  I would have left it clean and applied a liberal coat of grease.

9)  Reassemble it.  Now is a good time to replace the elevator bearings if you have any doubt at all about them.  It will never be easier to replace those.

10)  Re-balance your stabilator balance arm.  Not particularly difficult and perhaps not required but again, it is apart anyway and there will never be a better time.  No special tools required.  You might need to make a few shims or put some washers under a bolt or two.

11)  Check a couple of ADs.  Again, it is all apart anyway and now is a good time to be very thorough about it.

It is a bear of a thing to wrestle.  Probably the most nerve wracking thing I've done to an airplane.  Not difficult if lots of preparation time is available, the work area is clean and well lit, and you have all the tools.  They sell a tool kit and you should buy it or have access to one as the work is near impossible without it.  You can make the tools (except for the pilot reamer) but there is no economic reason to do so.

You will need:

 - alignment pins,

 - alignment bushings,

 - pilot reamer,

 - various cleaners, de-greasers, and loktite goop

 - calibrated inch-pound torque wrench

 - calipers

 - paint

 - lots of nerve and patience

William

Hi,

William did a good job describing it.   Last I heard, the tool kit was around $250.00.  Johnston Aircraft was selling those.  It is somewhat tedious and there is a learning curve. In the beginning, there were some owners, that tried installing them their selves under supervision of an A&P (I think).  Dave Johnston of Johnston Aircraft is the US distributor.  After said owners unfortunately ruined some of the ADS horns and wanted a "Warranty" replacement, Dave came up with the idea of having a "mail order" business for owners to send their assemblies to shops who had experience in installing the Aussie horns. Of course Dave didn't like the idea of warranty replacement for somebody who didn't follow the instructions and ruined a perfectly good horn, but first and foremost, he was concerned about people improperly installing them. So, the "mail order" option was born and Johnston Aircraft, Clifton Aero, Webco Aircraft, and my Heritage Aero advertised the "mail order" option in response to Dave's idea.   

Please do not misunderstand me, I am not "Trolling" for work, we have plenty at this time. And I am not saying that a competent owner/A&P cannot do it.  They can do it as long as they follow the instructions. But it does take some time and some precision.  And yes, you have to be fast installing the balance arm in the horn.  That's best done as a 2 person job to get it done in a matter of seconds.  It also helps to put the balance arm in the freezer.  But you still do not have much time to get it together and lined up.  Now, one other important thing to consider is that the AD does reference Piper SB 1160 which regards the stabilator torque tube condition and minimum dimensions.  That has to be in "spec".  If not, there more than likely will be play in the tail once it is all together.  So, if you need a new torque tube, that is around another $1700.00 and there is a procedure to drill/ream out the new holes in the new torque tube to line it up with your stabilators.  That adds additional work and time to the project.  

I have also attached the instructions to install the ADS horn. 

Best Regards,

Cliff Wilewski

Heritage Aero, Inc.

I would follow up that the service Cliff is mentioning is a good one and an AME (that has not done this already) would want to seriously consider that.  This is not something just anyone can do.  You will need the appropriate qualifications.  

Re-assembling the balance arm onto the stabilator cables with the appropriate clevis arrangement and shims is not a trivial task.  Fishing those little washers between the clevis parts and onto the 1/4" bolt from the back while being unable to see what is going on is a huge exercise in patience, and that is with all the experience and technique to help.  (You assemble it without the washers using a spud from the front, and the slowly work the bolt in from the back while slipping the washers into the gap between the bolt and the spud.  Coat the washers in grease to make them sticky.)

My point is that it is not something an owner does while the local AME looks over his shoulder.  Get it done properly.

William

Thanks for all the info. I decided to go the mail order route and have the assembly built with the Aussie horn by the Johnston folks.