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MD-RA Inspections

darc_one

I'm New Here
Hopefully other Canadian builders can provide some insight regarding the pre-closing inspections.

My questions are:

- how many pre-closing inspections did you scheule?
- to what point did you close the skins on the rudder, vertical stabilizer, wings, ailerons, etc
-what are the inspectors looking for in particular?
-do the inspectors have an opinion on priming?

Cheers,
 
MD-RA Pre-cover inspection done once !

Hello !

I had my RV-8 MD-RA pre-cover inspection done last Dec 27. The whole inspection process lasted approx 3.5 hours. I can respond to some of your questions below. Mind you that every case is different. It is largely based on the builder's project workmanship and the quality of work done.

1) How many pre-closure did I schedule ? --> Just one !

I have an aerospace manufacturing background, and throughout my project, I've been occasionally supervised by a professional structural mechanic. Therefore, I had full confidence in the quality of my work. I waited until my empennage, wings and fuselage were ready for pre-closure inspection to do just one inspection. Some builder prefer to have their project looked at more often by MD-RA.

The first inspection is $650 CAD approx, all the subsequent inspection are $300 CAD+. Therefore, if you can limit the number of inspection visits, that's better for your wallet.

2) Closed the skin on flying surfaces:

After MD-RA inspection. You need to have at least a corner of a skin you can lift for the inspector to look inside your flying surface. Once my tail feathers were inspected, I was able to finalize riveting and roll the leading edges.

3) What are the inspector looking for:

Simple, quality and workmanship. Each inspector will be different. He doesn't have the time to look at all the rivet. But if he detects poor workmanship, be sure he will look deeper in the build to find flaws.

4) Primer !

My project is entirely primed with aerospace grade epoxy primer. Therefore, there was no discussion about that.

During my inspection, the Inspector did not find real snags. He made good suggestions though, which I have to report as done on the next inspection. Considering the quality and workmanship put into my project so far, the MD-RA inspector has given me the green light to proceed until pre-flight inspection. No intermediate inspection will be required until then.

I hope this helps
 
- how many pre-closing inspections did you scheule?
You could get away with one pre-cover inspection for everything, probably not advisable for a first time builder as there is value in having the inspector look over your building techniques and giving advice going forward. There is the expense for each inspector trip to your shop, but view that as Training and orientation of their expectations moving forward.

- to what point did you close the skins on the rudder, vertical stabilizer, wings, ailerons, etc
They have to see everything inside, they don't use mirrors or borescopes, usually means one side skin riveted & other cleco'd loose. Vert & Horiz with skins rivetted to front spar & most ribs, with rear spars just cleco'd open. You get the picture.

-what are the inspectors looking for in particular?
Technique, build quality, mostly they want to know that you know their expectations.

-do the inspectors have an opinion on priming?
MD-RA requires internal surfaces are protected, could be rattle can, could be 2 part epoxy, whatever, they just want to see some protection.
 
As others have said, you can get away with one pre-cover inspection (I did). But if you do that, have one or more knowledgeable people have a look at your work as you go.

They are looking for the quality of your workmanship which includes following aircraft standard practices (AC43.13B). Edge distance on bolts/rivets, number of threads showing on torqued nuts, drilled shank bolts and cotter pins where required, over driven/under driven rivets, rough metal edges, etc etc.

Depending upon your inspector, you may get by with priming mating surfaces on the interior. For example, the wing rib and the area on the skin where the rib will be riveted. The open area between the ribs and spars on the skins may not have to be primed. Check with your inspector!

I had one pre-cover inspection on my -8 and then the final inspection.

Cheers
 
Thx for the prompt replies, extremely helpful.

While I expect there to be a learning curve, my educational degree is in Engineering, so fingers crossed I can figure things out. I really appreciate the experience of others that have gone through the actual process, vs myself reading and inferring what may be involved.
 
#1 Make friends with an experienced builder to help you through the tricky bits, provide advice and demonstrate technique.

#2 Have said friend inspect your work before the MD-RA does.

Then go ahead with MD-RA inspections. You have to pay for this part. As others have said, the Inspector is there to evaluate your craftsmanship. If he likes what he sees (organized shop, good riveting technique, attention to detail) you will breeze through and end up hangar flying for an hour afterwards.

My final inspection on my Rocket was all paperwork. He asked me if I had built the (flying) RV-9A sitting next to it, and when I said yes, he moved on without an inspection. I suppose he figured that proved I knew what I was doing.

V
 
-do the inspectors have an opinion on priming?
MD-RA requires internal surfaces are protected, could be rattle can, could be 2 part epoxy, whatever, they just want to see some protection.

Alclad parts *are* protected, by design.

That said, my opinion is that priming mating surfaces is a good idea, and priming the entire inside surface of an alclad skin is overkill. For non-alclad parts, I agree that full priming is a must.
 
Remember that you started on the tail surfaces first. Logically that's where your worst workmanship will be found. Give them a really good looking over with a critical eye and fix anything you see that should be done better than you did on your first try.

Definitely get a good set of eyes to look over your work before calling for inspection. No MD-RA inspector wants to condemn your work - they want to be able to complete the inspection with few snags written up. A good quality of workmanship exhibited in the pre-cover will undoubtedly make the subsequent inspection an easier ride.
 
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