Whee's over sized rear windows

[whee]

Nic asked for some pics of my rear window so I figured I start a thread to post the pictures in.

When preparing to build the rear window frames I decided I wanted bigger windows so my kids would have a better view. The whole point of my airplane is to fly with my family and I want them to enjoy it. What's the point of low and slow flying if you can't see outside.

I looked at pictures of Maules with observation windows and looked closely at the pics Jared posted of his windows and developed a plan of my own. I decided to follow the airframe structure because it was easy and athletically pleasing to me.

The top and aft portion of the window fit into steel "U" channel we formed and welded in place



The bottom of the window is held in place with screws/nuts that attach to an aluminum window sill. The sill is riveted to tabs that are welded to the fuselage.









AKschu had a great idea to use some appropriate size aluminum flat bar rather than nuts on the screws that attach the window to the sill. Drill and tap the flat bar and use it in place of the nuts. Great idea.

For the window on the right side I slightly modified the middle door support tubes. The perimeter door frame tubes are unchanged but the support tubes used to stiffen the frame I change a little.



I simply attached the window to the middle door skin with screws and nuts. I guess I don't have a good pic of that.





There is a significant weight penalty associated with big windows but I really like them and think they are worth every ounce.

[John Bickham]

Whee,

thanks for posting that. I have almost the exact windows. Stole the idea from you or Jared? My rear window is just a bit lower at the top. I was wondering what thickness of acrylic sheet you decided to use? I am a little concerned about drumming of the large surface area.

[whee]

Drumming was a concern of mine also. Based on the recommendation of others I went with 0.118”. Pretty much everyone said any thinner and the windows and doors would drum.

[svyolo]

I have had a couple of guys at work asked me if my side windows would be convex (outward) I said I wasn't planning on it but they both said visibility out and down is better. The shape would also dramatically stiffen the windows, maybe even allowing thinner windows without drumming. Anybody tried this?

[Chris In Milwaukee]

I have had a couple of guys at work asked me if my side windows would be convex (outward) I said I wasn't planning on it but they both said visibility out and down is better. The shape would also dramatically stiffen the windows, maybe even allowing thinner windows without drumming. Anybody tried this?

I believe Dennis and Donna both had this done for their patrol windows. Not exactly the same as your 4-place back windows, but they had bubble-type windows made and might be able to offer some insight.

[whee]

Bubble windows are somewhat common on Cessnas. They add downward visibility and stiffness to the window but there is a slight speed penalty and they do distort things at the corners of the bubble.

Bubbling the rear windows would have allowed the use of much thinner window material but I don’t have the ability to make them myself and determined that I didn’t want them enough to pay someone to make them.

[way_up_north]

Bubble windows are somewhat common on Cessnas. They add downward visibility and stiffness to the window but there is a slight speed penalty and they do distort things at the corners of the bubble.

Bubbling the rear windows would have allowed the use of much thinner window material but I don’t have the ability to make them myself and determined that I didn’t want them enough to pay someone to make them.

I`m also very interested in the bubble window mod....I didnt know fellow bearhawkers had done it...cool

[Chris In Milwaukee]

They aren’t deep bubbles, probably less than an inch. They’re nicely done. First obvious downside is the windows won’t swing all the way open. But it’s a minor thing.

[nichzimmerman]

Thanks for sharing Whee. I'm having a bit of trouble visualizing the cross section of the lower passenger window sill. Looks like the window is bolted to a black bar sitting on top of the sill, bit how is that fastened to the sill?

[whee]

Thanks for sharing Whee. I'm having a bit of trouble visualizing the cross section of the lower passenger window sill. Looks like the window is bolted to a black bar sitting on top of the sill, bit how is that fastened to the sill?

The sill is bent in a ‘L’ with the window sitting on the sill inside the short leg of the L. Look at this picture closely and you can mostly see it. Sorry I don’t have a better picture of the L



My windows are tinted so that black bar is just the tinted window making the part of the sill it is attached to look black.

[nichzimmerman]

Ah, I get it now. I bent the flange on my sill downward so I'll either have the bolts on the bottom side (unless I do fabric interior) or rivet a strap on the outside with an edge sticking up to bolt the window to.

[Flygirl1]

Yes, Dennis and I had all our windows bubbled. I was so used to it in my Citabria, I just had to have them. The hardest part, besides paying for it, was making a schematic for LP Plastics to work from. Where you start the bubble is kind of important and how much bubble is also important. Ours turned out to be about 1/4 to 1/2 inch too much bubble, especially in the front as our doors do not open all the way. I wouldn't change them though as they really add some extra elbow room to the cabin. I can rest my arm on the window ledge very comfortably and can see my brake lines if I want. As far as any speed loss, I can't say. I'm getting 152 TAS at 24/24 at 3K MSL and even if there is any loss, I still like them enough that I would do it again. I THINK it was around $1000 for all four windows, but that was 5 years ago. LP Plastics was great to work with too. Another point to make is I've been told it is something you can do yourself. We didn't even try. Clarity was really important to us. Didn't want any of that distortion in the curved part, which I think would be pretty hard to do making it yourself. Ours has just a touch of distortion at the bend of where the bubble starts. And I think they look good on the Patrol. ;-)

[way_up_north]

The bubble window is a great idea, do you have any pictures of the windows or a link to a build site.

If you were to do it now, any recommendations on what you would do diffrent?...can you design it with a ledge to act as an arm rest?

When you say do it yourself, you mean do your own window in your kitchen? With compressed air. You know of other builders that have done it successfully?

[Flygirl1]

I'm still looking for those photo's. I took about 4000 of them ( unfortunately in no particular order ) and I sent Mark G. a USB of most of them. My USB is corrupted, whatever that is, and I'm having a hard time doing anything with it. Mark might be able to send you a copy of his??? There are photo's in the forum of the windows I believe. The only thing I would do different is have the bubble a little less. I think it's actually more bubbled than the Citabria, a little bit. Keep in mind the window bubbled like that will not let that portion of the door open all the way. We used gas struts to hold it open and they work great and in 350 hours have only hit my head on it once. The arm rest comes naturally with the window ledge that is built into the frame. Mine is a bit wider due to the fact I have added an interior that has an extra piece that covers the window ledge and the top portion of the interior. There is also a photo of that somewhere in the forums. As far as "do it yourself window bubbling" Dennis read somewhere that somebody used his wife's oven by building a box that extended the oven to fit his needs as far as bubbling windows. I believe you can use a form or compressed air. I'm positive it has been done but i don't recommend using your wife's oven, unless she is a really cool wife or not one that uses her oven much. ;-) It will probably take a lot of practice pieces to get the process down though. If I find my photo's I'll post ASAP.

[podo]

Hi, Donna. I too really enjoyed my Citabria's domed window and would like to do that for my Patrol - they look so good on yours. LP Aero Plastics shows a part number for the Patrol and lists a 1.5 inch dome. Do you recall if that is the amount of bubble you consider to be "1/2 inch too much bubble"? I snipped out of there product catalog here.