Windshield mounting hole: 1/2" from edge enough?

[haribole]

Working on fixing the windshield, and after trimming the bottom edge on the pilot side the position for the mounting holes is about 1/2" from the edge, wondering if this is enough or if I should be trimming some more.

[Bdflies]

1/2" seems about right. I don't think I'd go closer, though. The real big thing, is to drill the hole big enough that the screw doesn't bear on an edge and be sure to debur and smooth the holes.

Bill

[Battson]

I wouldn't go any closer. You want to oversize those holes quite a lot, because of thermal expansion etc.

It's mostly the clamping action which holds the side of the windshield in place. The forward movement of the plane in the air pushes the windshield backwards, and outwards at the sides. That's be biggest force on the windshield. So you want a have a flat piece of metal to line each side of the windshield where it gets attached, and spread the load more evenly over the plexiglass.