BC12D tail flying wires

[OlindeASP]

I recently got my Bc12d, and the flying wires on the tail are very rusty and definitely need to be replaced, I am a bit lost sourcing the parts for this, would this set work, and have all that is needed to replace all 4 of the rear flying wires?
Thank you!

https://www.aircraftspruce.com/catalog/appages/taylorcrafttailflywire-set4.php

[Scott]

Yes but they have no stock. Maybe try direct with Univair or Wag Aero

[edmundcammack]

Hello,
does anyone have the correct tension for a 1940 BC-65 tail wires? Thank you.

[Hank Jarrett]

They aren't set with tension. You level the plane in roll referencing the tube at the back of the seat sling and then adjust the wires to the stabs are level and the fin hinge line is vertical. It takes a few times going around to get everything straight. After the plane has sat for a while they will probably NOT still be straight. Adjust again to get everything level and vertical. When all the surfaces settle in you will find the wires will come close to the same tension and if you "pluck" the top wires they will have near the same tone side to side and the bottom wires will also have their same tone. If they don't, things will still be settling in. Check after a few flights and re-adjust for level and vertical. The sound will be a slightly low thump when plucked.

[edmundcammack]

thank you. working on that today and will update.

[Hank Jarrett]

Just remember you DO NOT need to get all of the wires extremely tight. When the tone goes up that means the tension is high. It means you might need to loosen the opposing wire instead of tightening the tensioned one. You want just enough tension to bring the rudder hinge vertical and the elevator hinge line horizontal. The wires hold them in place and you will only need a low "thump" when you pluck them. Extremely tight wires don't make the tail stronger! It is "just tight enough" to hold the surfaces straight.

[edmundcammack]

OK,
thank you.

[edmundcammack]

the tail was perfectly level horizontally and vertically. the upper wires had a low twang similar to one of the larger strings on a bass guitar. the bottom wires were loose, no twang. i tightened the bottoms equally and just enough to get the large string bass guitar sound which did not change the vertical or horizontal level of the tail. It was just one turn. All seems good.
thank you.

[Scott]

Did you determine the reason the wire rigging changed?

There are a few things that can cause this, one relatively common reason is corrosion of the fuselage tubes in the attachement area.
S

[edmundcammack]

I didn't see anything obvious but will look more closely there. The bottoms have been a little bit loose for a while and the last couple of annual we decided that they were OK. this year I used a new A&P, who is a tube & fabric man as well as an antique taildragger man and he thought that we should address the tension. Will post again if I find corrosion or other problem.
Thanks.

[3Dreaming]

The tail wire fittings can give a little causing the wires to get loose. I remember Forrest Barber saying that when he would do a test flight on a F19 he would do a snap roll to the left and right, and when he would return he would tell them to tighten up the tail brace wires.

[Hank Jarrett]

Forrest could do a lot of things in a brand new F-19. I kind of doubt I would be inclined to do that in my 82 year old BC12-65! I have found that on old planes it is better to adjust everything level and vertical and fly a bit and check again. When you don't need to adjust any more and the tone on top is the same and on the bottom (the longer wires will have a slightly lower note) you are done. Check them at the season change and watch for things to move after they have stabilized. That could mean that something structural is going on. I "strum" all of the tail wires on every pre flight. Sudden changes are a good time to NOT fly and look a bit deeper for why.