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[Hawkmoon]

https://nypost.com/2018/05/02/southwest-airlines-flight-makes-emergency-landing-due-to-broken-window/

Southwest is in the new again.

Passenger Alejandro Aguina said the crack was located on the “outside.”

“On my way to NJ for work and #Southwest957 gets a window crack. Only outside crack so we’re all safe,” he tweeted. “On our way to NJ in new plane. Thanks to the @SouthwestAir crew and pilots for handling it professionally.”

I thought the outer layer was the pressure layer. There was an article just a couple of weeks ago showing a plane in which the inner layer had simply fallen out due to heavy turbulence, and a passenger was trying to push it back into place. How many layers does a 727 window have, anyway?

[Fly320s]

Airbus have three window layers, so I assume the 737s do too.

The inner window layer is just window dressing, literally.  It is only there to hide the fittings of the real window. 

The middle layer and outer layer are both designed to handle the pressure.  You'll see a small hole in the bottom of the middle window to deal with condensation and pressurization differences.  I think the middle window does most of the grunt work in resisting the differential pressure.  The outer pane is typically flush with the aircraft skin.

The photos in the article look more like delamination than an actual break, but it is hard to tell from the photos.  I don't know how thick those panes are or if they are laminated.

What is odd, is that the window in the article is in a location similar to the other Southwest plane that had a window blow out.  Probably just a coincidence.

[Hawkmoon]

What is odd, is that the window in the article is in a location similar to the other Southwest plane that had a window blow out.  Probably just a coincidence.

That's what they want you to believe.

[Fly320s]

That's what they we want you to believe.

Fixed. 

[KD5NRH]

Airbus have three window layers, so I assume the 737s do too.

That sounds right.  One to handle all the kids poking at it, or people bouncing their carryon off of it, that essentially just protects the next one, which shares the pressure handling with the outer one.

Of course, now that Surmet has finally figured out how to use what Scotty gave them 32 years ago, maybe the next generation of airliners can have a one piece fuselage outer shell.

What is odd, is that the window in the article is in a location similar to the other Southwest plane that had a window blow out.  Probably just a coincidence.

Wouldn't that be a fairly common spot for any debris that got deflected off the wing to strike?  Didn't catch what phase of the flight they were in, but an undetectable crack from a strike on the runway would be a perfect stress riser for that kind of damage once there's a couple pounds of pressure differential.

[Fly320s]

Wouldn't that be a fairly common spot for any debris that got deflected off the wing to strike?

Maybe, but the window that was broken by the engine piece was even with the back of the wing.  Kind of a lucky shot.

[Hawkmoon]

Maybe, but the window that was broken by the engine piece was even with the back of the wing.  Kind of a lucky shot.

Ahem ... phrasing?

[Jamisjockey]

*expletive deleted*it like this happens way more than people realize and is handled like an emergency out of an abundance of caution on the part of the flight crews and ATC.
It only made national news because it happened to SWA just a week after they had a major emergency that killed someone.