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RV12 rear window spider cracked

yeogene

I'm New Here
Hello from a new to the forum and a almost RV12 owner. I stopped flying in 1993 as a PPSEL working on my instrument rating. Now retired and able to fly again as a Rec pilot in a eLSA and was lucky enough to fly a RV12 before I bought a plane kit.

Anyhow, I am in the process of buying is low hour bird that has the back window spider web cracked above the fuel filter. Builder tells me it is from fuel splashing and is common.

Is it common?

Is it a concern other than looking bad?

If I purchase a new piece from Vans is it a direct fit?

This plane does not have Nav lights, I like them for the safety component.

If I but the nav only light from Vans does that include the fiberglass and mounting brackets as well.

Is there a more cost effective option?

Plane is in the local Rotax certified shop right now getting a 100 hour inspection and ADSB in out installed and should be done soon.

Thank you in advance for your thoughts
Gene
 
I would say that everyone is gonna have to replace their original Lexan rear window unless they keep it in a perfect climate controlled hangar.

I just replaced mine with the form fitting plexiglass one. No problems at all.

The new one works much better.
 
Is it common?
Yes, fairly common. Gasoline hitting the drilled or cut edges of the polycarbonate window causes it.

Is it a concern other than looking bad?
Not that I know of. It's not going to get any better, though.

If I purchase a new piece from Vans is it a direct fit?
Yep. I installed the pre-molded acrylic replacement, it's great. You will need to drill it, unless you go off-script like I did and put it in with Sikaflex. I don't know if they still sell the flat polycarbonate rear window, but do yourself a favor and just don't.

If I but the nav only light from Vans does that include the fiberglass and mounting brackets as well.
Call and ask them...

Is there a more cost effective option?
Yep. I installed Kuntzelman nav lights on mine, after installing the Van's fiberglass wingtip fairings. Everythign works fine, but it was a lot of work. Were I to do it again I'd probably buy the kit from Van's.
 
You may want to download the updated RV-12 Section 40 KAI on Van's web site to see what is involved with installing the lighting kit.

If the original builder did not include the wiring for the lights through the ribs, you will have to fish the wires. Depending on how old the kit was, you may want to also upgrade the wing electrical connectors to newer AMP style self-aligning connectors. The strobes can induce noise in the headset audio if you do not install the noise filtering capacitors.

Last, it you want a white position light on the tail you are pretty much on your own to come up with a solution. I put mine on the fiberglass cap that goes on the VS. I think Van did something similar on his personal RV-12.

John Salak
RV-12 N896HS
 
Van’s lighting kit

I used Van’s lighting kit to install lights on my legacy RV 12. I highly recommend them. I also installed the new style wing electrical connectors.
This is pretty time consuming, and you will be cutting holes in your wings for the landing light and the strobe/navigation lights.
I also installed the plexiglass rear window, not a big job, but you will be trimming the center rear of the window to clear a brace.
Van’s instructions for all of these are very good, you just need to follow the closely.
 
I changed out my rear window after 4 years due to crazing and went to the new molded version. Six years later, no issues.
 
RV-12 rear window spider cracked

Mine developed these spider cracks about 4 years ago. I have not changed it yet as I don't think it is an air worthy item. But I will change it one of these days.

I think it is a common problem from fueling.
 
The crazing will happen eventually anyway .... fuel just makes it happen quickly.

My RV-12 has always been kept in a hangar and has never been parked outside, except for the occasional fly to a restaurant for a breakfast or burger & fries outing.

The rear window has never been cleaned with any kind of chemical cleaner and I hand fuel using a Mr Funnel ... have never spilled a drop of fuel.

If the light is right, one can easily see the signs of crazing beginning where the Lexan makes the bends to meet with the sides of the fuselage. I seemingly have no surface cracks yet ... but the stress marks are clearly visible.
 
The bending of the flat lexan into a curve puts a lot of stress on it which probably makes crazing inevitable as John says. That’s why I wanted the molded window to avoid at least that contributor.
 
Guess I have been lucky! 2013 RV12 here and no cracking or crazing. I keep it in a hangar and I don't ever remember splashing fuel up onto the window. I've only owned it for a couple of years.
 
The crazing will happen eventually anyway .... fuel just makes it happen quickly.

My RV-12 has always been kept in a hangar and has never been parked outside, except for the occasional fly to a restaurant for a breakfast or burger & fries outing.

The rear window has never been cleaned with any kind of chemical cleaner and I hand fuel using a Mr Funnel ... have never spilled a drop of fuel.

If the light is right, one can easily see the signs of crazing beginning where the Lexan makes the bends to meet with the sides of the fuselage. I seemingly have no surface cracks yet ... but the stress marks are clearly visible.

My lexan stress fractures were on the pilot side - I have never had a fuel side issue - at first i thought something had scraped it somehow....
 

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My lexan stress fractures were on the pilot side - I have never had a fuel side issue - at first i thought something had scraped it somehow....

THATS not stress fractures, THIS is stress fractures -- to quote from a movie :rolleyes:
 

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THATS not stress fractures, THIS is stress fractures -- to quote from a movie :rolleyes:

Yeah that's what I thought too - but I ended up getting a few more of them - just longer and bigger. Vans Support confirmed them as "stress" fractures. Beginning of the end of the lexan flat sheeted rear window.
 
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