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L21 Greenhouse Glass Modification

Mine's just the way the Army had it - clear. 8) To me, the tint just makes it harder to see out. The temp isn't an issue for me either. If it's 110 degrees, I already have a hat on and the door open! :lol: If it's less, it's not really all that hot, is it? :roll:

Tom
 
L-21 glass

Flying Miss Daisy said:
Higher elevation closer to the sun. Cathy does not care how hot the Supercub is it is a Supercub
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It is bright, great visibility but HOT in summer COLD in winter!! I did it once N83679 you can see my ad. I do not think I would do it again. Univair has the window good price I think $125
 
one piece L-21 top glass

Are there any pros and cons as to making the top glass on a L-21 of one piece? Other than it being easier to handle two pieces? I can only find one reference to this here. That being that someone named Mark at Big Lake has done it. Does the dimension change with large temperature variations thereby causing cracks and distortions? Has anyone else done this?

Another question - There are some references to using 3/16" on the skylight. Have there been a lot of failures with 1/8"? cracking? breaking out?

Thanks for your input.
 
skywagon8a said:
Are there any pros and cons as to making the top glass on a L-21 of one piece? Other than it being easier to handle two pieces? I can only find one reference to this here. That being that someone named Mark at Big Lake has done it. Does the dimension change with large temperature variations thereby causing cracks and distortions? Has anyone else done this?

Another question - There are some references to using 3/16" on the skylight. Have there been a lot of failures with 1/8"? cracking? breaking out?

Thanks for your input.
Click to expand...

1/8 is all i have ever seen used....
One piece dont sound fun....
 
I have the Airframe's with L-21 glass and powder coat. The frame is PMA'ed, so allows the glass with a logbook entry. We are discussing the new CF baggage piece... so you might consider that, which means keeping the angle short for the front baggage, and no lower support behind the dog leg.

Would I go back to Airframes????? YES! I am still on the interior panel portion of my plane, but I like their workmanship.

John, the hat is so that you don't sun burn your head like I do, and Cathy has more hair to protect her scalp!

I burn up when it heats up here, if it is over 70 with the little skylight I am looking to remove the heat scat on the front of the firewall, and have an auto drip of cold water pour on me....

looking forward to flying full glass
 
Mark used the factory one piece skylight from LP Aero Plastics. I got the same part but haven't installed it yet.
 
The main benefits of one piece I can think of are less parts, and unobstructed rear visibility. It is super easy to cold brake a piece of lexan and make the crease.

skywagon8a said:
Are there any pros and cons as to making the top glass on a L-21 of one piece? Other than it being easier to handle two pieces? I can only find one reference to this here. That being that someone named Mark at Big Lake has done it. Does the dimension change with large temperature variations thereby causing cracks and distortions? Has anyone else done this?

Another question - There are some references to using 3/16" on the skylight. Have there been a lot of failures with 1/8"? cracking? breaking out?

Thanks for your input.
Click to expand...
 
L21glass on a pa18

dose any one know if you need a field approval to put the L21 green house on a PA 18
 
That's one way. The Piper drawings are probably approved data, so if you decide it is major, you can cite them and mail the 337 to OKC. Opinion.
 
I agree with both Steve and Bob. The following is the FAA's definition.

PART 1—DEFINITIONS AND ABBREVIATIONS

Major alteration means an alteration not listed in the aircraft, aircraft engine, or propeller specifications—
(1) That might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness; or

(2) That is not done according to accepted practices or cannot be done by elementary operations.

Minor alteration means an alteration other than a major alteration.
 
A bit of thread creep, my apologies. I have been looking for "real" plexi (not Lexan) for my WB SC with L21 glass. I recently found that George of LP Aero has the glass in stock. LP Aero 724-744-4448 ext 233. Make sure you tell him it is for a WB so he can trim it long/wide.
 
I'd do L-21 smoked, and smoke both skylight sections. I did my 12 like that and I really like it.
 
Just don't comment on the dusty wings. This pic was taxiing out for the first flight after rebuild. I figured if everything went good (it did) THEN I'd wash it.
 

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I owned an L-21 style SC for several years. As others have noted, the visibility is really nice. Also, when rooting around in your baggage compartment, you can actually see what you’re doing. I like em.

MTV
 
I prefer the looks of the standard windows myself so that's what I'm going with in my cub rebuild.
 
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From the inside looking out 21, for the outside looking in STOCK and either way a plexiglass lower door!
 
The trick to keeping it light is using standoffs from the gingerbread and tubing for extra support . Then using thin Acrylic. If done properly it should weight no more than D window with metal headliner. Now D window without headliner and thin Acrylic will be lighter but may not hold up if you run big loads stuffed to the top. I carry passengers a fair amount, My wife can wear a helmet and have nice seat cushion even with the metal headliner. But anyone over 5' 8" hits the Headliner. So that means neck bent with hemet hitting headliner or going to thin camper pad for back seat. Most guys will hard butt it for a hour but after that they start to bitch. If I recover I would go to L21 just for passenger comfort, I don't even need to do it for the cool factor because I already have Bushwheels. I used .060 acrylic on both sides and door of my D window cub this spring it has held up fine. Thin tinted lexan for the skylight. Lexan is nice for the skylight because you can bend it in a brake. Ryan at CAC plastics says they have a new acrylic they bend with simple heat tapes. My thin lexan skylight will vibrate quite a bit when I am slow with full flaps. But has no cracks or issues after over 500 hours. That yellow cub is how I would want mine to look.
DENNY
 
One downside we tend not to worry about in around here is hot weather. For the guys down south what is it like on a 100 degree day flying with the door closed.
DENNY
 
Yeah - it is illegal around here to fly with door closed - makes no difference whether lower door is acrylic or not.

Here is my take - a Cub is very close to the slowest thing aloft. Things behind you are way more of a threat than things in front of you, especially in this day of complicated glass cockpits. My next J-3 will have L-4 windows. Maybe smoked overhead.
 
I know you guys down south like to fly around with everything open but go stick a week of camping gear, wife, put down blanket (wife likes it so it stays handy), and open charts in the back(she likes that also). Now open the door and see how much stays!!! We went up North to Bettles in June and it was HOT (90 degrees is smoking for Alaska) so I said lets fly with the door open and my wife said sure, better pictures!!! Next thing I know everything is being sucked out the door!!! I am trying to drop flaps, turn crosswind, close the door and not hit the 10 other planes in the group. Up front is fine, but if you have a passenger that is not used to being in the wind it may be an issue. So If you do L21 think of ways to keep cool in the sun!
DENNY
 
What is the rough weight penalty for greenhouse glass over standard?


Sent from my iPad using SuperCub.Org
 
I merged your thread with several others on the subject so you might check the previous page of this thread.
I like the L18/L21 glass even in Texas. I like the look of the "D" windows but "function over form". ;)
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If you are installing a metal headliner with "D" windows I wonder how much weight difference there really is?
 
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