What makes an RV junk?

[mturnerb]

Originally Posted by Larry DeCamp

How do you define a bad flush rivet ? Many pics here display excellent results , the result of very sharp dimpling, tight hole fit and square approach from the set tool. A lot of rivets don’t appear to be Lindy Winners, but are structurally 100%.
So, short of smilies and tilted factory heads, how would you make the call ?

I'm proud of most of my riveting - I sure drilled out enough that I didn't like. I think there is some definite condescension on the part of some folks on this forum about the quality of riveting. And I also think that there are cosmetic considerations as well as structural. While building, I figured out pretty quickly that sometimes it's better and safer to accept a less than perfect cosmetic result - especially if the rivets in a given row or assembly are mostly good.

Here is a direct quote from Van's own section on riveting - taken from the Alcoa Aluminum Rivet Book (admittedly taken out of context - read ALL of section 5 before taking this to heart):

"The standards to which driven rivets should conform are frequently uncertain. In addition to dimensions and perfection of shape, inspection is concerned with whether the drive head is coaxial with the shank (not "clinched") and whether there is excessive cracking of the heads. It has been determined that even badly cracked heads are satisfactory from the standpoint of static strength, fatigue strength and resistance to corrosion. (Poorly set and cracked) rivet heads were tested in tension to determine how well formed a head has to be in order to develop full strength. The tensile strengths of all the rivets were within five percent of the strongest. The test indicated that minor deviations from the theoretically desired shape of head are not cause for concern or replacement. The second rivet that is driven in any one hole [is] likely to be more defective than the first because the hole is enlarged and [the] rivet will be more likely to buckle and form an imperfect head. Tests have shown that very small rivet heads are sufficient to develop the strength of the rivet shank, even when the rivets are subject to a straight tensile pull....where a large head is not needed for appearance, smaller sizes of drive head should be used to decrease the required driving pressures."

[Larry DeCamp]

This clarification covers lots of anxiety . I was comfortable with less than 1.5 x shank diameter shop heads in shear, but did know about the tensile evaluation.
It appears that VAN and other authorities leave factory head cosmetics to the ?eye of the beholder?.

[spatsch]

I think your question is not precise enough to get a good answer. I put my junk next to the street and most of the time it's picked up before the trash truck shows up. So it seems my junk is somebody's treasure. Same applies here.

I think there are 3 categories you can break this into which make some sense:

Safety:

I have never heard of a prepunched RV causing bodily injury because of bad riveting. Even more so on a quick build kit where most important rivets are already done by Vans. Sometimes when you read this side people really obsess about rivets. Not quite sure why as the data doesn't reflect a relationship between safety and rivets at all.

From a safety perspective you should look at the engine and everything that's attached to it (e.g. fuel system). That's what kills people at least in the statistics I have seen. Even little things like silicon sealant in fuel system can kill.

So the engine and it's systems will define what's junk from a safety perspective in my book.

Maintenance:

That's a much longer list. E.g. bad workmanship can cause cracks. Poor rivets might get to a point where they need to be replaced. Bolts might not be properly tightened etc... . Those things will all be visible in routine maintenance so as more of those you have as more time you will spend on the ground fixing things.

How much of that "junk" you are willing to deal with depends a lot on how much flying vs. working vs. money you have.

Aesthetics:

Your opinion is as good as mine.

Oliver

[Vern]

Park your junk next to an old typical rental or trainer and suddenly your Vans junk shines like a diamond. Fly them and you will choose the junk over a worn out rental.

In the Air Force I once parked next to a B-52 which had just landed from a low level flight. Several airmen were using grease pencils to circle the popped rivets from that one flight. A 1958/62 era jet!

[larrynew]

This might win the prize for “Junk RV” that actually flew.

[Sue]

Originally Posted by larrynew

This might win the prize for ?Junk RV? that actually flew.

Cosmetically doesn?t look that good
But structurally doesn?t appear to be
Affected? Perfect no, could it cross the
Atlantic without the left side of the
Cowling comping off, probably.

[Ted RV8]

I?ve found that when the workmanship suffers so does the rest of the build and rigging quality.
To me there is no place for ?that?s good enough? with an airplane.
I?ve seen some builds that there is no way I?d fly in it.
Guess I?m just picky, just remember it?s your life when your flying something.

[JonJay]

As mentioned, if you know what you are looking for, you can inspect the critical systems and structures. An RV that is not ?well crafted? may still be very airworthy. I know of many.

[Capt]

The one thing that makes up how we humans decide on what's good enough or not about anything in life are the EYES!! We are very visual creatures and that alone makes us pre judge a lot of things in life.
Imagine how many A/C out there much older and worked harder than our Vans that are flying daily with a zillion imperfect rivets etc? LOTS!!
A good friend of mine once said ...."stop trying to make it visually safe and enjoy flying it" ....been doing that ever since with a few rivets that smile back at me everytime I polish my plane and the working rivets I have get cleaned and left alone, gets thru it's annual inspection every time by a well know RV fixer

I've flown little Cessna's to Airbuses that looked tired, I'm still here

[Ironflight]

I think some may have misunderstood my comments above. I am not so much looking for every single rivet to be perfect. I am very satisfied with a number of bad rivets (even quite a few) in an airplane if they are spaced out. My comments were about airframes I have seen where almost every rivet was underset...or every rivet was smashed beyond recognition. Those airframes need to be completely disassembled in order to be made anything resembling acceptable. That’s my definition of a junk airframe.

And as I said - you can replace poorly installed systems - but the bones are the bones...