Tailwire javelins

[5152062]

515A is moving along but I need some help. Where is the correct placement of the tailwire javelins? Mid point between the two wires? This is fine for the lower set as the javelins will be more or less in line with the direction of flight, however, the upper set will be skewed to the direction of flight; if the upper is placed in line with the direction of flight then, when viewed from the side, the javelin will be skewed to both the horizontal stab and tail.
Am I being too anal? What is correct? thanks

 

[lwford]

The javelins are to keep the wires from vibrating and coming apart. Just make it look good and have them near the center of their span. They will do the job regardless of looks. I will also add not to make the wires overly taught as your going to break them. I believe Bill Reeves had that happen to him years ago on his Bellanca. When adjusted properly, you should get a little deflection as you try to twist the rods with your hand. We are all Anal on this bus! :lol: Lynn the crate

 

[5152062]

Many thanks. I'm always amazed how the little problems often cause the most grief.

 

[Dan Cullman]

Tierod/flying wire tightness has been covered here in distant past. During my very first flight in any Bellanca [my 14-13] in 1970, I experienced an upper wire failure. I could hear a "ca-chunk" while flying and couldn't understand what happened. About six months later, the other side failed when my Dad was flying. Both wires broke at the lower jam nut. McWhyte was still making wires at this time and I called them about the issue.
I was told to tighten the wires "to a low bass tone." Not very scientific, but it works. Apparently over tight wires are prone to failure.

 

[Rob58]

Both Lynn & Dan have offered good advice. The wires do not need to be real tight to do their job, in fact too tight is bad as it places more stress on the structure. I use the same approach mentioned by Dan: use sound to tune the wires. If the tension on any pair of wires is not closely matched then all of the work will fall on the tighter wire. There is one variable that I am still trying to figure out... harmonic, sympathetic resonance (vibration). I had my prop dynamically balanced recently and learned a lot about how nearly everything in an aircraft structure has a resonant frequency. The "javelins" (actually called "battens" in the Bellanca documentation) serve to dampen vibration in the tailwires as Lynn mentions. They are important.