Patrol pilot window frame overlap detail

[podo]

Does the leading edge of pilot window frame overlap the windshield attach screws or get folded behind them? I show here 3 pics, each with a different attach method for the windshield screws. One has the post trim piece dimpled with csk screws through the trim and into the windshield. Another uses csk screws with cup washers, it seems, directly on the plexi of the windshield, and a third with the window trim folded behind and truss head screws attaching the windshield. How would we use countersunk screws on the windshield and keep the expansion gap?
Thanks,
Pete

[jaredyates]

I'm sure there are any number of good ways to do it. My mindset when working with plastic was to spread the load whenever possible. By doing it the way the yellow and red planes are done, the whole trim strip helps keep the window captive, like a giant washer. When I did it I didn't use flush head screws but I do like those better. I think there is merit to oversizing the holes in the plastic, which will allow for some expansion and contraction with temperature changes. On the red plane I wonder how one would go about weather stripping, but then again I've not been especially happy with my weather stripping in the past.

[spinningwrench]

I talked to the owner of the Red airplane which was in the booth. The plastic fairing was added later. You can see the slight raised lip which acts as a wind deflector to avoid wind catching the edge of the window frame.

[stinger]

IMG_2064.jpg

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my window frame sits behind and note the slight outward bend in windscreen securing panel this defects the wind . Stinger

[joehmason]

Build it like Mark's Patrol (the red one pictured above). I have my front window trim pieces overlapping the windshield trim piece and the windshield fairing. It holds the entire window frame out and away from the door and left window sill. It created large gaps (3/8" or better) at the front along the bottom of either window frame where A LOT of cold air comes in (right next to your hand on the throttle quadrant). To fill the gap I put sticky back foam on it but plan to modify that front window trim piece later this year. You can see in the attached picture the gap created at the bottom of the left side window.


IMG_2646.jpg

[500AGL]

The red plane photo is Mark Goldberg's Patrol. The builder chose to simply wrap the trim in, as in Texas keeping the cold out isn't usually a problem.

The downfall as stated above is the lack of any sealing ability.

As I have been flying that Patrol, once it started snowing inside the cockpit I added the air deflectors as a helpful remedy to lessen the influx of cold air, and mostly, snow.
I had added the same defectors to a previous cub I owned and they had worked well. Using the existing screw holes means it's a non-intrusive addition or removal.

The "break" or 45* bend is enough to create a low pressure behind it, and so instead of air forcing it's way into the cockpit, it's now a vacuum sucking air outward (very slightly). This naturally stops any snow flying across in front of your face.

The deflector is just a flat piece of 032-040, depending on your liking, with one edge bent to a 45. I got a bit creative and milled in some text and made a joggle to step out over the bottom windshield fairing.
******

That all said, Dave Lenart may chime in here because he keeps coming up with better renditions and I think his current build is likely the best way yet. He added a piece under the windshield (as i recall) that has a super small but effective 45* outward break, bridging the gap to the side window. Then, he added a 45* inward break to the leading edge of the window trim, so when you close the window the two 45* angles meet up and the window trim break overlaps the windshield trim break.

It really helps to have photos, so with luck he'll post up few. Of course he may charge you a royalty for using his idea as it took a few airplanes to figure out the best way.

pb

[jaredyates]

Sounds like a great Beartracks article!

[500AGL]

To expound further on the above idea from Dave, I’m not at my windows yet, but here’s a prelim peak what I’m doing on my door.

Caveat; My door will be overlayed with glass which helps this slightly.

- Boot cowl has a 45* break in the trailing edge between the door hinges.
- Door trim angles down to match when closed, with a slight forward leg that lays against the boot cowl skin.
- Due to the door hinge points being further forward, the assembly will open out away from the skin without rubbing. (The key here is to have the leading edge at or behind the hinge bolt axis)