Empennage Slop

[Doc]

Howdy: My horizontal stabs and vertical fin have some slop when slippd over and bolted onto the posts - obviously the reason for the bracing wires. My question is this: How much play (slop) is reasonable, and should a thin brass sheet shim (my IA's thought) be used to wrap around the posts to reduce the slop? The mounting bolt holes are not oversized and an AN4 bolt fits nicely. Thanks. Doc

[Robert Lees]

Re: Empennage Slop

Can't do any harm

[jgerard]

Re: Empennage Slop

AN4 is oversize. should be .1875" (3/16")

[Forrest Barber]

Re: Empennage Slop

Somebody already drilled them out!! as previous stated they were 3/16th . Be careful, there is an E.O. to drill and ream to fit 1/4 in. about .248. Maybe use plated oversize bolts?? If when rigged you can move the forward stab attach point , there is a problem.

[Hank Jarrett]

Re: Empennage Slop

Sounds like it has been "fixed" once already (oversize bolt). I would look it over very carefully to make sure there isn't more damage and see where the slop is coming from. Repairs to repairs usually mean you need to fully rework rather than just shim. I would be uncomfortable with oversize bolts AND shims for looseness. Something is going on and now is the time to fix it right.
Hank
I am assuming you have the covering off and the fin is exposed.

[Doc]

Re: Empennage Slop

Howdy: My keystroke mistake - I meant AN3, but I appreciate the thoughts. Should there be any slop - I mean, should this application be a press fit? Doc

[Guest]

Re: Empennage Slop

Howdy: My keystroke mistake - I meant AN3, but I appreciate the thoughts. Should there be any slop - I mean, should this application be a press fit? Doc

If the play is in the empennage put an internal sleeve in the stub, edge weld it. Use thick walled tubing, weld a rossette in the existing hole after the sleeve is in then redrill to an undersize and ream to a light drive fit.

If the fabric is on make a 12" x 12" sheild plate with 1" hole in the center to put over the stub. Pack wet towels on the fabric side. Use tig or gas.

Oops! forget all I said, you already said it was not the bolt hole! Guess I need to learn to read better!

[Guest]

Re: Empennage Slop

BTW- brace wires will not prevent the slop if you have an elongated bolt hole. They are there for other reasons. You can tighten the bolt for momentary solution but the problem will continue to return after a few hours of flight.

[Guest]

Re: Empennage Slop

Howdy: My keystroke mistake - I meant AN3, but I appreciate the thoughts. Should there be any slop - I mean, should this application be a press fit? Doc

They should slide on and off quite easily by hand or with a little thump with you hand.

Sometimes a rubber mallet will be required IF you get it skewed so that it binds.

No press fit though.

[Robert Lees]

Re: Empennage Slop

Agree, not a press fit.

Interestingly, there was an (old) AD on Austers that of course came from the Taylorcraft design, requiring the insertion on a "strengthening tube" to be welded inside the fuselage stubs, because one came apart in flight.

The fact that the Auster model in question has a certified gross weight of over 2000lb seemed to have missed the then Auster designer's calculations (and also bypassed a lot of our current CAA inspectors, who are of Auster vintage themselves).

Thank goodness for the good ol' FAA in publishing Taylorcraft AD's on the net.

Rob

[crispy critter]

Re: Empennage Slop

Howdy: My keystroke mistake - I meant AN3, but I appreciate the thoughts. Should there be any slop - I mean, should this application be a press fit? Doc

Doc,
Some play is aceeptable. I can move my stab tips up and down threw about a 2-4 inch range (maybe not that much but does have some play) with the wires off and the bolts in place. The bolt holes are snug on mine and fit tight.

[Dick Huish]

Re: Empennage Slop

On The Model "d" There Is A Doubler Tube Inserted And Fusion Welded (just Heat,no Wire) Dick