Rear Window Installation

[rex ervin]

I have 1/16" lexan trimmed to 3/4" larger than the opening on all sides and cannot get it into position.

Should I trim it more or does anybody have any suggestions on how to get it installed with minimal trimming?

Thanks,

Rex Ervin

[Glenn Patterson]

Rex,

The window may not go in as deep as you might anticipate due to the fabric. Take a scrape of the lexan and gently tap it in a round the fram incase there are any bits of fabric and glue holding it out. Make a poster board pattern directly from the window until you perfect its shape. If you have the window shaped to the pattern then push it in as far as it will go. The window can be secured with the trim at the door frame once it is in snug.

Hope that helps
Glenn
BH727

[Ed.Meyer]

I am in the process of fitting the rear window frame on the Patrol QB and am not clear about how it gets finished at the front next to the door/front window. I see in the post by Glenn Patterson on 1/16/14 mention of "the trim at the door frame..." but am not sure how this works to get a nice even surface for the aluminum skin at the edge of the door to close against. Any photos would be a big help.

[Dan R.]

Rex-- I thought you would be flying your Bearhawk by now. The more I do the farther behind I get. Dan R. from Hales Landing.

[rex ervin]

Thanks Glenn, that helps a lot.

Dan, I just sent you a private message. Good to hear from you.

[Glenn Patterson]

Rex,
You are welcome. If you can leave the door side a little long then it gives you something to grip while you are perfecting the fit. Trim the window to its final length & gently tap the Lexan in with a wide block for its final fit.
Glenn

[Ed.Meyer]

I am in the process of fitting the rear window frame on the Patrol QB and am not clear about how it gets finished at the front next to the door/front window. I see in the post by Glenn Patterson on 1/16/14 mention of "the trim at the door frame..." but am not sure how this works to get a nice even surface for the aluminum skin at the edge of the door to close against. Any photos would be a big help. I posted a comment to Glenn's post but I think I should have used 'reply' instead. Hope this is not an unnecessary duplicate.

[Battson]

So to clarify - are you installing the window frame itself, or installing the window into the frame?
I see the original post was about the window, but I think you're talking about the frame?

[Ed.Meyer]

Yes. It is the frame I am working on. It looks like it needs to go behind the former at the rear of the door in order for the door to have the flat surface to close against but then to provide for installing the actual window later is stumping me.

[Glenn Patterson]

I am not sure how the window on the Patrol fits. Fitting the rear windows takes great care as they need flow smooth & clean into the fabric lines and stringers so they perfect with the fuselage body lines. Getting the window in or out will stand out. Use strings and straight edges. Eric Newton has some window pictures on his Patrol site. I am sure if you could post a picture there is a veteran that will help you. Some of the solutions will come with patience and looking at it from every angle, My gut instinct is that you are talking about the window frame at the door and the frme should not be going behind the former. . The glass has to slide past the former into the frame. then a trim angle goes over the front of the glass to cover the end of the glass. The door flange overlaps the end of the rear window & trim angle. If you find your self fighting the door skin it is possible to shim under the door skin to get the surfaces to overlap cleanly. If fabric goes into the frame inside & out then allow for that when setting the width of the slot for the glass as well.

I am sorry for the delayed response as I have been away for a while.

All the best,
Glenn.

[Glenn Patterson]

Here is a snapshot & a sketch of our rear window at the the door former. The lexan is cut short of the door edge but long enough to still rest on the former. The trim flashing is stepped as per the photo. I also attached a quick sketch that shows how the pieces overlapped. We installed a trim cap on the inside of the door frame for a wear surface to protect fabric. We formed a channel on the inside of the door frame protector & concealed the fuel lines in the door trim so things do not catch or dent the lines.
Hope this helps if you have not resolved your concerns.

Our glass trim angle is actually secured between the door frame & the door frame wear protection trim with no exterior fasteners as shown in sketch. Sr. moment. It is nice & clean with the door closed. The window fits super tight in the frame and the trim flashing just secures the end & keeps it from sliding out. Use sealant along the edge of the glass under the flashing to prevent water sneaking in between the parts.

Glenn
BH727

[svyolo]

My B model came with a 2 piece window former. I am not sure I like how it all goes together, especially with the fabric.

I was thinking about making a new frame out of .032 Chrome Moly. CS some #6 screws, and weld them in place. Grind the heads/welds flush so they are not visible below the fabric. Use the screws as studs to mount the plexi.

Easy to install, cover with fabric, replace later. Slightly heavier.

I don't have any experience with fabric covered airplanes. I understand that I have to wrap the fabric around the former and attach it to the inside. This seems easier than using the kit parts, with less risk or buggering up the fabric job.

How is this done on other fabric covered planes? Basically it is just a big trim ring, covered with plexiglass.

[Nev]

Does anyone have any photos of their rear window installation they can post. I’m struggling to visualise how it goes together. Also how the fabric joins to the window surround on the left side (4-place QB).
Thanks in advance.

[Mark Goldberg]

On the left side the fabric gets glued into the window frame. The channel where the Plexiglas goes. Only on the kits from the last two years or so will you see the window frames like is on your kit Nev. Mark

[N942VT]

I'm assuming all the new QB kits are similar with the aluminum window formers. Make sure the joggle is outward and the flush heads of the rivet are on the outside, shop head inside. Use a piece of masking tape to find the lay of the fabric and you can adjust the standoffs to make the fabric lay in those channels and have a smooth transition to the upper longeron and stringer below. Fabric gets glued into the channel, I use small blocks of wood covered in parchment paper stuffed down in the channel. Careful not to shrink too tight around those windows or they can distort, especially on the inside.

[Nev]

Brilliant, exactly what I was after.

[svyolo]

Nev;
For several reasons I chose not to use the kit window frame, one of them being my lack of experience with fabric jobs. I also wondered how it would interact with the interior panels. I made a window frame out of aluminum angle and riveted that to very slightly modified kit standoffs. The inside of the frame mounts the cutout of the interior panel.

I think the thing I didn't like the most was after mounting the window, applying and painting fabric (in my case Oratex), then and only then did I try to muscle a thin piece of flexible Lexan into a thin, flexible assembly of aluminum sheet, which itself was now apart of the aforementioned fabric job. I had a piece of Lexan cut and slid it into the frame. It was tight enough I decided I didn't want to risk trying to do it when I had a bunch of fabric glued to the inside of the frame.

My way may not be better, but it was lower risk, at least for me. The kit frame would probably be a little lighter than mine.

[N942VT]

You can spread the seam a little even after the fabric is on if needed to slide the window in.

[Nev]

Thanks for the tips here gents, all really good to know and a big help.

[svyolo]

One of my caveats is "my lack of experience". Because of this I can see Murphy rearing his ugly head and screwing up my fabric job in a couple of different ways. I chose a slightly different way that hopefully keeps Murphy out of the room.

[coosbo]

Make sure the joggle is outward and the flush heads of the rivet are on the outside, shop head inside.

I just wanted to confirm that the flush heads should be on the outside and the shop heads on the inside of the cabin. It looks like in your first picture the shop heads are on the outside. Your pictures are very helpful. Thanks!

[Mark Goldberg]

Colby - on the right side of your fuselage - the most aft windows that are riveted to the cargo door skins - they have to sit flush against the aluminum door skins. On the left side - the rivets tails need to face inward so the window frames can sit flush to the attach points. Mark

[N942VT]

The reason for the flush head and joggle to be on the outside is so that the fabric does not contact the shop head of the rivet. I had one do that and was concerned about it wearing through eventually.. I turned the rivets around after I took the picture above. I'm not sure that in every case it's a problem, depends on the angle from the tube or stringer to the window channel. A piece of masking tape can be used to show how the fabric will lay.