Rudder rebuild

After 8 years and 875 hrs. on my -7A, I'm looking to either reskin or rebuild the rudder. Numerous rivets at either the forward or aft end of several stiffeners have cracks coming from them.

I'm thinking of replacing the skins, stiffeners and AEX while reusing the spar, counterbalance and tips.

I'd appreciate any thoughts or insights on my plan as well as any tips and ideas to produce a first class result. I built the original rudder and am just trying to minimize effort, cost and downtime.

Thanks, Mike

I am just starting to fly our 7A and I was wondering as to why the cracks are forming. It seems to me that the years and number of hours are low. FCan you shed light as to the cause.
Thanks
Dave

That's why I'm looking for thoughts and ideas to minimize their recurrence potential after the rebuild. Several that are 1/8" or less I haven't stop drilled, yet. As they get up to 1/4" length, I've stop drilled them with good results.

Mike

I am doing this very thing right now! Vans sells a rudder kit for $360. I bought the parts you described for $180 (pro seal too).

For minimum down time, I would order the entire kit and build new. To save money, I would piece it together.

I skipped the pro seal even though I bought some. I fabricated aluminum angle to sandwich the trailing edge. I drilled LARGE holes in every other hole so I could get my pneumatic squeezer onto the rivets. The angle clecoed to each side kept things straight while I worked every other rivet with the squeezer. I didn't totally set them but I got close before finishing off in traditional back rivet fashion.

Many builders say get yourself an -8 rudder but I rebuilt the -7 (-9) rudder. I'm not sure if you would go back into phase 1 if you fit an -8 rudder... But with the -8 you won't worry so much about the trailing edge and others mention it flies/feels better.

I'm currently painting which is a huge learning curve for me...we'll see if I am paying for an education when in the end I may have to have it professionally done anyway.

I am not flying quite yet, but this is what I did to hopefully reduce this very common problem: http://home.comcast.net/~jmjula/images/empennage/rudder/r9_rtv.jpg. Basically I globbed RTV in every corner of the fwd part of the stiffiners and globbed the proseal around the aft end when the wedge was riveted in. Don't know if it will prevent the cracks yet, but time will tell.

I recommend buying the entire rudder kit...

As suggested in a previous post, I recommend buying the entire kit as you can build at your leisure while continuing to fly the cracked rudder (after stop-drilling, of course). This is how I handled the cracked rudder on my -4. I built the second rudder using 0.020 skins and ProSeal on the faying surfaces of each rudder joint as well as globs on the trailing edge. On the first rudder, I used globs of RTV along the trailing edge, but did not do any bonding. The new rudder is much stiffer and slightly heavier but has not cracked after 9-10 years since replacement.

One detail to note is that, at least on the -4, one needs to remove the rudder briefly to fit the new rudder spar and rod ends to the vertical stabilizer as all these holes are layed out by hand. Once this is done, the old rudder can stay on until the final switch is made.

tkatc said:

Many builders say get yourself an -8 rudder but I rebuilt the -7 (-9) rudder. I'm not sure if you would go back into phase 1 if you fit an -8 rudder... But with the -8 you won't worry so much about the trailing edge and others mention it flies/feels better.

Click to expand...

That may be good and all but Vans decided that the spin recovery is inadequate