Flush side windows has anyone done it?

[jetdriven]

We’ve got this plane in the shop in the client wants us to mill or sand a 16th off of the edge of the window so that when you put it from inside the plane to mount it it’s sits flush with the sheet metal. It looks like a good idea especially for a speedy plane like a Mooney, but is anybody done this? Some discussion on how it was done and how it looks like when it’s done and whether it’s worth doing would be much appreciated. 

[MB65E]

Sounds like a great idea. Get thicker windows then mill them down. He’ll probably still want a flat bead of sealant. 
If pressurized-no way. 
-Matt

[Fly Boomer]

2 hours ago, jetdriven said:

We’ve got this plane in the shop in the client wants us to mill or sand a 16th off of the edge of the window so that when you put it from inside the plane to mount it it’s sits flush with the sheet metal. It looks like a good idea especially for a speedy plane like a Mooney, but is anybody done this? Some discussion on how it was done and how it looks like when it’s done and whether it’s worth doing would be much appreciated. 

Here is some advice:

https://mooneyspace.com/topic/24662-m20c-rear-window-replacement/

[Andy95W]

Sounds like a huge waste of time, but I’m glad you own the shop that gets to do the work!

I could almost understand doing that when installing the front windshield, but the side windows?  What would that add, 1/10 of a knot?

My question would regard other high performance aircraft.  Does a 58 Baron have flush windows? A TBM?  Citation?

[Aerodon]

Oh but it would look so cool, just like jet windows.  But I would think you really have to know what you are doing with material types, surface finish etc.  I believe the EVO windshield blowouts were caused by scratch marks on the outside edges.  Even in non-pressurized, you would not want to be doing anything that causes stress risers.

Another reason for doing it would be to install a 1/4" windshield in a 3/16" slot.

I saw a 'tube video with an STC's windhield in a 401 - no holes, a series of U's milled into the thick windshield to make sure there is no contact between the screws and plexiglass.

Aerodon

 

 

 

[Shadrach]

I look forward to seeing it. I don’t think it will add any speed, but it will look cool to the small percentage of people who notice it. This is sort of the maintenance equivalent of music for musicians.

[LANCECASPER]

11 hours ago, jetdriven said:

We’ve got this plane in the shop in the client wants us to mill or sand a 16th off of the edge of the window so that when you put it from inside the plane to mount it it’s sits flush with the sheet metal. It looks like a good idea especially for a speedy plane like a Mooney, but is anybody done this? Some discussion on how it was done and how it looks like when it’s done and whether it’s worth doing would be much appreciated. 

I look forward to seeing the addition you're able to build on your home with the hours of labor it will take to do this . . lol. This should be a "time and materials" job, not a quoted job. He should pay for a set of windows as part of the deposit and every additional replacement window that needs to be ordered should be paid in advance. If it was so easy he would be doing it himself. 

It would look great if it came out perfect, but I can see a few windows being set to the side after the milling wasn't perfect for him. The black trim that Mooney uses gives it a finished look and I doubt that he'll see a 1/2 knot speed gain from all that money spent. Will anyone ever meet his expectations? Probably not, but the two extra bedrooms, 2 baths and the game room will come in handy. 

[philiplane]

this is purely cosmetic. There is no speed gain, since you are not lowering the flat plate drag area at all, or even measurably reducing the form drag. 

No one other than the owner will even notice. But hey, billable hours are a good thing.

 

[Pinecone]

It sounds sharp.

Hmm, I will have to get @jetdriven to give me a price to do this when I have my windows done in a year or two.  He should have some experience by then and have it down in time.

[ArtVandelay]

I agree that this won’t actually make any difference, properly sealed they look flush.

[LANCECASPER]

It would be great if all of the window openings on Mooneys were exactly the same, it could be programmed in and cut down at GLAP, the manufacturer to fit exactly. But on our hand built airplanes if any two are exactly the same size it is purely by accident.

John Langston who worked at Mooney for years tells about how in 1986 when they started making the rounded openings for the side windows, that the pattern for the rounded opening in the metal that was used was a plastic cover off of a Folger’s coffee can. When the lady who did that piece went on vacation for a couple weeks and came back someone had thrown away her cover. She was sent to the grocery store to get another one and Folgers had changed that size that they used. They had to reverse engineer it from another airplane on line and finally did a drawing of it. 

[cliffy]

I'm willing to bet the aluminum curve varies more than the amount you want to trim off  in  thickness

These are all hand built, no to identical airplanes 

Pop a window out an lay a thin  strip of aluminum (on the inside) matching the curve and see how much it all varies from top to bottom. 

None of this stuff is close tolerance manufacturing  Just look at how the rivets are set. Highs and lows in the surface.  

[jetdriven]

On 1/27/2024 at 11:27 AM, LANCECASPER said:

It would be great if all of the window openings on Mooneys were exactly the same, it could be programmed in and cut down at GLAP, the manufacturer to fit exactly. But on our hand built airplanes if any two are exactly the same size it is purely by accident.

John Langston who worked at Mooney for years tells about how in 1986 when they started making the rounded openings for the side windows, that the pattern for the rounded opening in the metal that was used was a plastic cover off of a Folger’s coffee can. When the lady who did that piece went on vacation for a couple weeks and came back someone had thrown away her cover. She was sent to the grocery store to get another one and Folgers had changed that size that they used. They had to reverse engineer it from another airplane on line and finally did a drawing of it. 

That's really astounding, I was at the paint shop, trying to figure out the radius for the windows, I went back to the shop in Texas I was working at, and we fished out a later model J that had the radius windows, and then I tried to find something that was the right size and it was a Folgers coffee can fit it perfectly. I guess now I know why. I called the paint shop back and said use a Folgers coffee can, tape around that.

[jetdriven]

On 1/26/2024 at 11:50 AM, Pinecone said:

It sounds sharp.

Hmm, I will have to get @jetdriven to give me a price to do this when I have my windows done in a year or two.  He should have some experience by then and have it down in time.

I think this is going to be like the ovation interior in my M20J, one and done.. Typically you know you're just about finished when you're correcting mistakes made by the factory.

[cliffy]

On 2/3/2024 at 8:47 PM, jetdriven said:

That's really astounding, I was at the paint shop, trying to figure out the radius for the windows, I went back to the shop in Texas I was working at, and we fished out a later model J that had the radius windows, and then I tried to find something that was the right size and it was a Folgers coffee can fit it perfectly. I guess now I know why. I called the paint shop back and said use a Folgers coffee can, tape around that.

Measure it with a yardstick, mark it with chalk and cut it with an axe- precision aircraft manufacturing in the 1960s

If you ever saw how Cessna actually built their airplane back in the 150 172 days it would astound you I did! 

Rubber hammers were an essential tool