Cracking leading edge lens

After 350 hrs on our 14, I found both leading edge lenses with cracks. I am assuming that either or both causes would be A:vibration B:the screws holding the lens in place were too snug. I think I have found the cure in my "new and improved" installation and would be glad to share details if anyone is interested. I would like to hear if anybody else has had the problem and what you did to correct the situation. Happy New Year to all.
Roger

Have had the same problem on our club RV9A.

What was your solution?

after six years mine are starting to show some bulging around the two screws. I would also like to see the cure.

I would like to know...

me too, me too

In the meantime... Replaced a cracked lens 2 months ago: drilled the holes way oversize, then countersunk both sides of them holes. Used thick double sided tape to hold both anchornut strips onto the plexiglass. Filled the holes with silicon and only lightly tightened the screws until contact between the lens and the LE skin was made. Another small fillet of silicon around the cut-out to aerodynamically smooth out the lip et voil?... time will tell.

Well, Here is what I did. This is what follows after the metal parts are assembled. and after cutting to shape and sanding edges:
1. Cover front and back with Frogtape
2. Drill holes with specially prepared bit (1/8") or plexi bit
3. Counter sink for dimpled holes in wing HAND HOLDING counter sink. Do not use a drill or machine to prevent chattering of tool or counter sinking too deep.
4. Check that hole is just slightly larger than screw size. Clean all edges with fine sandpaper.
5. Use a tap the thread size of the nutplate (in my case it was a 6-32) and ream out the nutplate threads.
This will make putting in the screws much easier and you can then feel the amount of pressure the head of the screw is pulling the plastic.
6. Cover the edge and over the holes with a sdtrip of 1/2" electrical tape. Then cut or push a relief hole in the countersunk holes to allow easy access for the screws when installing in the wing.
7. Assemble the lens and nutplate holder with thin double stick tape. This will allow the lens to meet the cut out opening in the wing 99 percent flush.
8. Hand screw into wing just bottoming out the head of the screw with very little torque. I used 1/2" screws to ensure if any did vibrate out, it would be visible on the next preflight.

Here's hoping this works. Good luck to all and Happy New Year.

Well, Here is what I did. This is what follows after the metal parts are assembled. and after cutting to shape and sanding edges:
1. Cover front and back with Frogtape
2. Drill holes with specially prepared bit (1/8") or plexi bit
3. Counter sink for dimpled holes in wing HAND HOLDING counter sink. Do not use a drill or machine to prevent chattering of tool or counter sinking too deep.
4. Check that hole is just slightly larger than screw size. Clean all edges with fine sandpaper.
5. Use a tap the thread size of the nutplate (in my case it was a 6-32) and ream out the nutplate threads.
This will make putting in the screws much easier and you can then feel the amount of pressure the head of the screw is pulling the plastic.
6. Cover the edge and over the holes with a strip of 1/2" electrical tape. Then cut or push a relief hole in the tape over the countersunk holes to allow easy access for the screws when installing in the wing.
7. Assemble the lens and nutplate holder with thin double stick tape. This will allow the lens to meet the cut out opening in the wing 99 percent flush.
8. Hand screw into wing just bottoming out the head of the screw with very little torque. I used 1/2" screws to ensure if any did vibrate out, it would be visible on the next preflight.

Here's hoping this works. Good luck to all and Happy New Year.