> Bleed holes, Captain Joe explains, “allow for pressure equalization between the space between the panes of the window and the cabin interior. Without these holes, the pressure difference between the cabin and the space between the panes would lead to stress on the window.”
This doesn't refer to the double-paned outer window, the pressure window. It refers to the innermost protective pane, the "scratch pane" that keeps greasy fingers and portruding camera lenses from reaching the two "real" windows. It's the hole in the scratch pane people are asking about
> doesnt mean the inside one isnt there to protect the outside one.
The inner pane is typically half the thickness of the outer pane.
So whilst you could argue it cold be seen as a failsafe, I would say its primary purpose remains "double glazing" insulation.
The OAT at 30–40,000ft is very low and there is a lot of combined window area. So the importance of insulation is not to be underestimated. In particular on newer aircraft where efficiency is the name of the game in their design.
Also if it wasn't insulated, the windows might also steam up? Or does the air conditioning make it dry enough that this wouldn't happen. Foggy windows could also affect the pilot's ability to see, I suppose the flight deck windows must also be insulated.
> Or does the air conditioning make it dry enough that this wouldn't happen. Foggy windows could also affect the pilot's ability to see, I suppose the flight deck windows must also be insulated.
Depends on the aircraft but a typical design would connect the space between the panels to an air supply or otherwise a self-contained desiccator system.
Flight deck windows are completely different, typically three layers, two full thickness and one half thickness. All fully heat/chemical strengthened with additional anti-fog, anti-ice and moisture absorption systems built-in. The fact that some of them are sliding (i.e. openable) adds to the design complexity.
Doesn't this just put the stress on the other pane of the window? I don't see how it helps.
EDIT: Oh. It helps because otherwise the bit between the panes would be at a different pressure to both the interior and exterior of the plane. It would work just as well if the bleed hole were on the outside, as long as both panes are equally strong.
This is such a common annoyance on the modern internet. I've recently been playing Minecraft with my kids, with a few mods, and I've been irritated to discover that - unlike when I'd mess around with mods a decade ago - lots of the "documentation" for mods now exists only in video form.
Anyway, I built / slopped out this little wrapper for yt-dlp that I call tuber[1], and it has a feature for grabbing a video's subtitles and summarizing them with Claude, if you've got the CLI. I've found it really handy for those annoying cases where some video seems to promise info I want but I don't want to sit through ten minutes of bullshit.
Yeah, I'd rather read a 2 minute article than have someone stretch the explanation to 10 minutes for ad revenue or the algorithm or whatever the current YouTube enshitrification meta is.
The article claims it helps stop condensation, but I have several memories of little ice crystals and/or condensation that originate right at the little hole…
Most people don’t think along this axis. It’s the same reason why if you asked somebody how a toilet works or the functionality of P-trap (both things a majority have interacted with/seen more frequently than a plane window), they’d probably give you a blank stare.
so if I block it with my finger from takeoff to cruise I can create a little explosion? Or is the issue the repeated cycles of pressure weakening the material over time?
> Bleed holes, Captain Joe explains, “allow for pressure equalization between the space between the panes of the window and the cabin interior. Without these holes, the pressure difference between the cabin and the space between the panes would lead to stress on the window.”
The inner pane is typically half the thickness of the outer pane.
So whilst you could argue it cold be seen as a failsafe, I would say its primary purpose remains "double glazing" insulation.
The OAT at 30–40,000ft is very low and there is a lot of combined window area. So the importance of insulation is not to be underestimated. In particular on newer aircraft where efficiency is the name of the game in their design.
Depends on the aircraft but a typical design would connect the space between the panels to an air supply or otherwise a self-contained desiccator system.
Flight deck windows are completely different, typically three layers, two full thickness and one half thickness. All fully heat/chemical strengthened with additional anti-fog, anti-ice and moisture absorption systems built-in. The fact that some of them are sliding (i.e. openable) adds to the design complexity.
For the non-aviation folks, OAT means "Outside Air Temperature".
https://acronyms-suck.com
That's the scratch pane you are referring to.
Yes, it is made of cheap plastic and serves no structural or other purpose other than to protect the real stuff from annoying kids. ;)
EDIT: Oh. It helps because otherwise the bit between the panes would be at a different pressure to both the interior and exterior of the plane. It would work just as well if the bleed hole were on the outside, as long as both panes are equally strong.
Anyway, I built / slopped out this little wrapper for yt-dlp that I call tuber[1], and it has a feature for grabbing a video's subtitles and summarizing them with Claude, if you've got the CLI. I've found it really handy for those annoying cases where some video seems to promise info I want but I don't want to sit through ten minutes of bullshit.
[1]: https://github.com/epiccoleman/tuber
I feel the same with this article.
https://archive.org/details/sciencefromyoura00wood
https://www.faa.gov/lessons_learned/transport_airplane/accid...
I'll definitely be on the lookout next time I fly though but yeah. Maybe its not every window?
I also prefer a flight without get a feeling of a flying can.