RV-6 spar differences

Hi all,
I'm looking into buying an Rv-6. Saw a fine example, but it doesn't have the Phlogiston Spar.
My question, since I intend to do some aerobatics with the plane, is how do we determine if the Spar is well built in a non-Phlogiston unit?
Is it possible to inspect ( in a pre buy) the quality/ integrity of the spar?
Thank you very much.
Greg

You should be able to inspect the center section of the spar adequately by removing the seat skins. If that's not enough, you can pull the tanks and see more of the spar.

The "non-phlogisten" spars came pre drilled. So unless the riveting job is atrocious, or the doublers were tapered poorly, the spars should be fine.

I guess what I'm saying is that if the spars are a problem, it should be pretty obvious.

gongreg said:

Hi all,
I'm looking into buying an Rv-6. Saw a fine example, but it doesn't have the Phlogiston Spar.
My question, since I intend to do some aerobatics with the plane, is how do we determine if the Spar is well built in a non-Phlogiston unit?
Is it possible to inspect ( in a pre buy) the quality/ integrity of the spar?
Thank you very much.
Greg

Click to expand...

Take a good look at the rest of the airframe,,
Pull panels, look into areas not normally visible.

You should be able to determine in short order, the overall build quality.

And frankly, yes the spar is important,, but if I were looking at a potential failure point due to poor quality control on the part of the builder, I would start at the tail.

Good news!

That's good news, Mel. And I thank you very much for the answer.
I suppose, then, that an experienced mechanic in a pre buy would detect if it's good or not, which makes me feel better.
And I'll take a good look at the tail section too. Thanks, Derrik.

Sparring partner....

gongreg said:

That's good news, Mel. And I thank you very much for the answer.
I suppose, then, that an experienced mechanic in a pre buy would detect if it's good or not, which makes me feel better.
And I'll take a good look at the tail section too. Thanks, Derrik.

Click to expand...

Greg,
Sent you a PM, needless to say I am with Mel. You can see enough by looking in the stick well and through the inspection panels to see if he "boogered up" anything during construction. Building the spar is actually much easier than some other parts, Phlogiston just does "exemplary" work and anodizes everything.
When it arrives it looks like something that should be in a safety deposit box earning interest...

V/R
Smokey

Another thing, if the builder has pictures of the construction available, that would give you an indication. I set my AN470-6 rivets with an Avery C-frame and 3-pound hammer and made sure to get pictures; it was a highlight of building for me. I felt like Thee Olde Blacksmith hammering rivets in armor. The hardest part of the spar was tapering the doublers; the guys in the maintenance shop at American International Airways ran them through a bandsaw for me but it still took a lot of time with a vixen file to bring them to final shape. But even with a pre-built spar there can be problems; builders are ingenious at finding ways to drill, nick, and gouge a spar during assembly.

Oh, you might also want to look at the Operating Limitations. For my build, I had to declare in the Program Letter what maneuvers I would be doing in my Phase I and then make an entry into the logbook to activate those maneuvers in my OL. It does you no good if the plane is not cleared for aerobatics; I think (Mel can confirm) that you'd have to request new limitations and put it back into Phase I. On the other hand, if they are already in the OL and signed off then you know the maneuvers have been tested.

One other thing I'll mention. Make sure that there are 4 steel splice plates where the spars connect together. They should be fore and aft, bottom and top.

I have found at least one RV-6 that did not have the forward side splice plates.
They are all 4 necessary.

Mel said:

One other thing I'll mention. Make sure that there are 4 steel splice plates where the spars connect together. They should be fore and aft, bottom and top.

I have found at least one RV-6 that did not have the forward side splice plates.
They are all 4 necessary.

Click to expand...

Now,, THAT,, is very scary!!
Yikes!!

N184DA said:

Now,, THAT,, is very scary!!
Yikes!!

Click to expand...

Fortunately it was found on airworthiness inspection and hadn't flown.
Just glad he didn't get an inspector not familiar with the RV-6 who probably wouldn't have noticed.

Just one more reason to use a DAR with RV experience.