How far to rivet for mdra

Hello everyone I'm just getting to the point of riveting up my horizontal stabilizer. Should I just do one side so the other is available to peel up and inspect or should I rivet the front half Leaving the rear spar out to inspect.
The same goes for the rudder, do I even bother going part the main spar? Is there such a thing as not riveting enough for the inspection?

Rivetting Prior to Pre-Cover Inspection

Andrew, when I built the horizontal stabilizer and vertical stabilizer for my RV-9A, I fastened the rear spars with a few clecos only. The MDRA inspector asked me to remove the rear spars and he examined the inside of each component. Now to see the riveting ahead of the HS and VS main spars, he would have had to use a flashlight and long-handled mirror, but he was OK with that.

I left the elevator and rudder trailing edges undone for the pre-cover inspection. Same for the ailerons and flaps.

The wings were riveted with the exception of the forward few rivets in the lower skins. He carefully pulled the skins away from the spars and looked in each bay.

The fuselage was riveted except for the forward deck. I had plywood in the tail cone in case he wanted to crawl in there for a look. He didn't bother to do that.

The MDRA inspector can tell pretty early on how good (or bad!) your riveting is, so he doesn't have to look at every single rivet. Give him a reasonable chance to look at as many rivets from the inside as possible, and you will be fine.

Andrew:

Check with the MD/RA rep if you can; mine said that the days of the flashlight/mirror are gone. They want to be able to "easily" see your work. Having said that, there may be some wiggle room with individual inspectors. Mine made me open up an ancillary control I had fully enclosed - no flashlight and mirror.

Best to check now to save time later.

John

Every inspector is a bit different

Every inspector is different. My inspector was totally fine with mirror and flashlight. Schooner69 is bang on with his comments. You may not know your inspector at all when he first comes to visit. But fortunately the empennage is a pretty clear line to determine what to leave open. As Sledrider says leave the rear spar off on the HS and VS. Also, rivet the elevator frame together, but do not rivet the skins on the frame (rivet the counter balance skin on the skin with those two inner rivets you can't get when all closed up).

Once you inspector shows up he can easily see everything. Then start asking him about what he wants to see on the wings, and the fuse. write it down. Also ask if its ok to call him in a year or so just in case you have a question about what he wants to see. I did exactly this and my inspector was glad to help....but I was darn certain about following his every request. Nothing goes further in building trust then sticking to his request's even if you think they are odd or un-needed.

A fun one you will need to figure out is how to inspect the fuel tanks...do you close it all up, do you encapsulate the shop heads, but leave the back baffle off, or do you leave it all open for inspection. Best to confirm these details with you inspector as you build.

I have heard three different directions given by three different inspectors. They are not wrong....perhaps they have different experiences, or they see things in some peoples builds that make them want to check a little more then the next guy. I'm the same when I do inspections for work....i don't inspect every job the same, but when I see things that make me worry, I dig deeper or I ask that they call me more often to site.

On the project I bought the tail was closed. I had to drill out many rivets and open it back up for the mdra. So check with your inspector. They ARE all a bit different.

What do you guys think about priming rivets after they are set. the previous builder used rattle can primer and the rest of my work is AKZO the rear HS Spar was completed Hinges and all. It will be visible kinda. just wanted everything to match. I don't want and grief from an inspector.

Should be ok

I'm going to go out on a limb here as say that a light primer coat on the rivet heads should be ok. An inspector will still easily be able to tell a bad rivet from a good one.

Hi Andrew,

I can't imagine an inspector giving you grief about a light coat of primer on rivets, nor the different colors/type of primer used. If he did have a strong "opinion" on priming, unless it was obscuring his/her inspection, I'd politely refer to Vans Part 5 on the requirement to prime.

Regarding priming set rivets: Take a look at that rear elevator spar, how can the backsides of those skin to spar rivets adjacent to the spar realistically get primed? Don't get me wrong, I'm not saying its good or bad, I'm just saying you likely won't get the entire shop head... ok maybe with a brush or q-tip...... I'm sure not going to do that; besides, I believe they have their own corrosion resistance built in

thanks for the replys everyone much appreciated!