321 hours on the hobbs - Fixing the right elevator skin problem

Work sucked up all my time this past week, and I had to renew my CFI ticket by finishing an online course (that did not suck so much, but still took a lot of time). I was finally able to get back to the elevator again tonight.

After posting my latest screw up on VAF and becoming immortalized on the Aircraft - Specific link for the RV-8, and then on the front page of VAF with a "Dang it" caption from Doug Reeves, it was time to make a decision as to the solution to my dimple screw up on the elevator skin. I had several replies from differnt folks as to the best way to fix this problem. I decided to go ahead and do the following:

1. Stop-drilled the crack, which basically means that I had to drill out the hole that I had tried so hard to plug back up. As the following pics will show, now it is truly a figure 8 set of holes, but they will be filled prior to painting, and will not be visible once the paint gets applied.

This is a standard procedure to relieve stress build ups in areas where cracking occurs, and it applies to cracks in metal as well as cracks in other materials such as fiberglass, plexiglass, etc. The procedure us relatively straight forward - find the end of the crack in progress, drill a hole just slightly beyond the very end of the crack to allow the crack to migrate to, and stop it from cracking any further.

2. Flatten the dimple in the intended hole, and also in the matching hole in the stiffener, to provide as much support in the area now that I will be essentially bypassing it. I used the flat set in my rivet gun and the back rivet plate to flatten the dimples just as I did before. All it takes is a couple of light taps from the rivet gun and you are done.

3. Measure, mark, and drill 2 new holes, one on either side of the intended hole and the stop-drilled hole right next to it. These 2 new holes will provide two new contact points with 2 new rivets added to provide support for the area on the skin that was compromised with the unintended hole that was created when the skin slipped off the dimple die. I added the two new holes about half way between the intended hole and the holes on either side of that one. trying to keep the nice neat rivet line is the challenge here. We'll see how it looks after the stiffeners are back riveted onto the skin.

4. Cleco the stiffener onto the skin, and use the new holes in the skin as drill guides to finish match drilling the new holes into the stiffener

5. Remove the stiffener, debur the new holes in the skin and stiffener, and dimple them. This time I made certain that the skin did NOT slip off of the dimple die.

And here are the pics of the process. First one is after removing the existing dimples, and marking and drilling the new holes. Notice the figure 8 where I had to stop drill the botched hole in order to keep it from cracking. Click on the pic to get a larger more clear view of this. The new holes are also drilled adn visible:

And another one from the top side of the skin:

And finally a slightly blurry close up of the two holes that are now going to have to be filled. You can still see the crack that used to be along the edge of the dimple, which has now been flattened back out. UNfortunately this will be an eyesore until everything is filled and painted, since it is on the top of the elevator skin. Several folks have told me that as long as I have done this repair, I will never see a crack in this area again once everything is filled and painted. Worse case scenario is that I get to make a new elevator somewhere down the line, and maybe that is not such as bad thing either.

A note about the 10th Anniversary of 9/11

All I wish to say is simply this......

I am an American, and I am damn proud of that fact.
I have taken some time today to reflect on the events that occurred 10 years ago, and I hope that each of you managed to take at least a little time to do so as well.

During that time of reflection, something happened to me that I thought I would share:

As the thoughts of the 9/11 anniversary suddenly overtook me, my attention immediately turned toward the sky. I noticed that it was not "silent" as it was 10 years ago, when all aviation was grounded on that terrible day. Many contrails filled the sky from high flying jets, and the sounds of airplanes filled the air all around me - again, completely unlike that dreadful day 10 years ago.

It put a smile on my face to see and hear aviation happening all around me.

Peace and hope to all who protect this great country, and to those of us that are so blessed to live here...

314 hours on the hobbs, Finish the Rudder and Let the elevators rise!!!!!

....Some final thoughts on the rudder. Just a couple more pics to show the details of the temporary hinge pin that I had to forcefully remove in order to separate the VS and rudder as described in my previous post. See the etched marks where the 1/2 inch cold chisel was placed to try to hammer out the pin from the hinge. Nice thing to have to do to something attached your aluminum airplane, huh!

The marks on the curved part are where the cold chisel was place. The marks on the top part were made by the hinge as I tried to pound this little sucker out.

Next is the tip of the temporary hinge that I had to cut off with the dremel tool. Not a real good pic, but if you look closely, you can see the ridge that had built up on the end, right next to the hinge plate, which is why I could not remove it easily. Thanks a gain Van's for not elaborating on the need to drill out the hinges to final size. (Still pissed off about that!)

And lastly, a set of new temporary hinges from Aircraft Spruce (Actually made by Avery tools). I ordered these fr several reasons: They have the threaded end on one end along with a threaded holder for ease of placement/removal, and they are short enough to allow for full control surface travel one placed in the hinge. They don't have that stupid long extension that gets in the way. The threaded holder allows me to get leverage on the hinge via the screw threads instead of having to pound it out with a hammer. Of course, now that I know I need to finish drill all the hinge holes to the correct size, I don't expect to ever have a problem with this again.

Now on to brighter things - -no more rudder for a while -  on to the elevators, which make the plane go up and down......

The process is very much like building the rudder. Starts with stiffeners as the main support element for the elevator skins. Here is my little work table setup that I clamped to the work bench. I decided to trim the stiffeners outside this time to keep from messing up my inside workroom work benches. Thankfully the elevators are a bit smallers in all dimensions from the rudder, so all the structural pieces are a bit smaller as well. I clamped a small piece of partical board to the the end of the workbench to allow several edges to place the angle for the stiffeners depending the cut I needed to make, and used my dremel tool with a extension shaft that I got for christmas to provide a bit more control while trimming the stiffeners.

I use two different types of REINFORCED cutoff wheels. If you use a dremel tool, and I can't for the life of understand how you will be able to finish a kit like this without one, do NOT use the small flimsy non-reinforced wheels that typically will come with a standard dremel tool kit. Use the larger, reinforced ones, adn remember to where ear adn eye protection when you trim the stiffeners from the angle. Why use  dremel instead of the shears as Van;s suggests? Because the shears leave serrated edge on the metal and are not well suited fortrimming smaller parts. The edge has to be filed down to remove any stress risers, whereas the dremel cut is much easier to cleanup with the Scotch Brite wheel.

And a shot of pretty much all the equipment to get the job done. Be sure to buy the economy pack up cutoff wheels - you will run through many of them:

A shot of the rough cut stiffeners after using the dremel tool to trim them to initial shape. Edges are very sharp and jagged at this point, so be very careful handling these pieces..

Note that I always leave some excess from the cutline on purpose so that I can bring then down to final shape using the scotch brite wheel, which is much easier to control. I also take the time to get the tail end each stiffener small enough so that when the elevator is bent the edges of the stiffeners will not interfere with the skin.

Thes next three pics are of yet another screw up that may actually cost me a new right elevator skin. I had cleanup the stiffeners and dimpled them, and was then in the process of dimpling the right elevator skin. I thought I had developed a sure fire method to prevent pounding a dimple hole in an unwanted place on the skin, but I managed to find a way around it.... THe pics that follow are what is know to us builders as the dreaded figure 8 dimple, because that is what it looks like when you screw it up. The new hole is close to the actual hole and this creates the figure 8 effect. IN my case, I tried to smooth out the bad one with my flush set, which worked pretty well, but then I tried to dimple the original hole and ended up with a crack that I now have to resolve somehow. I have posted the pics to VAF to get some opinions as to the best method to try to finx this. Hopefully I won't need a new skin. The first two are on the underside of the skin, and the last pic is looking at it from the outside. Can't let this crack go unattended or it will surely continue to crack later on...

As a well known participant on Van's Air Force forums always says, "It's just one damn thing after another...."

Oh, and to finish up - went on the annual dove hunt with my youngest son and my neighbor, a fellow CFII and coworker. We caught a couple of pics of some awesome sunrises out there that I thought I would share. This is out in Northeastern Colorado in farm and cow country. I can't wait to see some more of these types of scenic views from the air. Hope you enjoy them.