EAA Technical Counselor

This year is off to a fantastic start!  Today was the first of what I hope to be many visits from an official EAA Technical Counselor.  I don't know if I'm lucky or if it's pretty standard fare but I was fortunate enough to have a total of three Technical Counselors show up.  I was extremely impressed with the experience and depth of knowledge these gentleman had.  Definitely a resource you should utilize when building your first, or even fifth plane.

The visit lasted about an hour and a half and included some official paperwork.  The rest of the time was going over the pieces and answering any questions that I had.  The most important thing was they said I am doing a good job and there were no major issues.  Here's are some items and pictures that may help someone on their build.

Riveting

Okay when it comes to riveting I am my own worst critic.  It's just not perfect and I want it to be perfect.  So when it's not perfect it bothers me, it really really bothers me.  My friends can look at it and say "Hey that looks great!", I look at it and I see all the little issues I know about because I did them.  They assured me this is completely normal, gave me some direction on how to improve a few of them and we talked about some of the techniques that show plane builders use to make thing 'perfect'.  In my case it's going to involve primer and paint in a few years.

Deburring

There are some areas on the skins that weren't deburred as well as they could of been.  My method was to debur enough that you wouldn't get cut.  Some of these hard to reach places just involve running a file over it a few times followed by a scotch brite pad and calling it a day.  I didn't do that well enough or missed a few areas.  For example in the picture below you can see it's had a pad ran over it but you can visually see it's rough.  I'm going to spend an hour or so and get these all cleaned up.

Cracks

Might a tad hard to see in the picture but I had a small crack in the skin.  This is what happens when you hit it with a wrench while taking on and off the elevators 30 times.  It's a tiny crack but if ignored can turn into a much larger crack similar to what happens when a rock hit your windshield.  The fix, oddly enough is the same as what you do with a windshield. 

To fix this I'm going to drill a 1/64th or so hole at the edge of the crack.  This will keep it from getting larger and then I'm going fill the spot in with some JB Weld.  Luckily I'm a pro with JB Weld so will not need any further instruction on that.

Bolts and Torquing

Over or under torquing bolts is/was a concern for me.  I have a pretty good torque wrench but new to such precision bolts I wanted to make sure I was doing it correctly.  What I learned is you find out the torque required to turn the nylon threaded nut and add that to the value.  So these AN3 bolts require 20-25 in lbs torque.  If the nut takes say 2 lbs of pressure to start turning then the range will be 22-27 in lbs.  So before I mark these I'm going to loosen them a bit redo them.  Not a ton of them so shouldn't take long and moving forward I know how to do it correctly.

Also the area where I added the additional 1/16th or so spacer needs the bolts replaced.  I up sized the rivets but used the bolts called out in the plans.  As you can see by the picture it's too shallow as you need a thread and a half at least clearance on the bolt.

Advisory Circular(AC) 43.13

Pilots know what an AC is and most will know that 43 deals with maintenance.  What I didn't know was AC 43.13 is a 646 page document that covers all sorts of building techniques. Specifically it's 'Acceptable Methods, techniques, and practices - Aircraft Inspection and Repair' . I went ahead and downloaded a copy and will start referencing it first when I have a question or need a better understanding of something.

In closing I can't stress enough how important it is to involve your local EAA Chapter on a build.  They're there for the same reason you're building a plane in your garage, a passion for aviation.  The reassurance you get that you're on the right track is priceless and having a team who wants to help you succeed in your project is also priceless.