Passenger Aircraft Windows
 

Does anyone know what the small metal thing embedded in passenger aircraft windows is called and what it is for? You sometimes see ice forming around it after you've been flying for any length of time. After staring at it for the best part of 12 hours recently, my best guess is that it might be some sort of safety device for detecting fatigue.

It's a hole, designed to let the air vent from the space between the inner and outer pane.

SMOC

....Love to know what airline that was that gives you little better to do for 12 hours than stare at a small vent hole !

Well, snce we're into minute details, how about this: Why is the little hole on the outer pane, and not the inner one? is there a specified reason for it?

It's not...... The hole is on the inner window. It is a breather that also helps to detect when the window seal is leaking. Cabin pressure forces air through the hole and will leave a small circular stain on the inside of the outer window. This will also be accompanied by a fair amount of condensation between the windows.

Already well answered thus far - I just wanted to add that the hole is to minimise condensation between the inner and outer plexi-panes. The hole is almost always located at the bottom center of the inner pane.

The hole is there to make sure all pressurising loads are on the outer pane, as the inner pane is there in case of outer pane failure and does not take any load until then. :ok:

They didn't tell us this in school :confused: They told us it was to decrease fogging/condensation issues. Perhaps this is a welcome side effect to your posit ?

Be careful, some aircraft have 3 panes, outer, middle and inner, the inner being an accoustic or scratch pane. The middle and outer being the pressure panes, with the mid pane having the vent hole.

The "Breather hole" does allow cabin Pressure to the outer pane which is usually a plug type installation and the primary load taker, the middle pane can usually, upon failure of the outter pane, take 1.5 times the normal load. The breather hole also helps prevent fogging!:ok:

The inner panes are most useful on military trooping flights, when the passengers like to carve their intials in the window with their bayonets... :ugh:

The hole is never on the inner scratch pane, as 4 year old kids on a 12 hour flight with nothing better to do, would plug them all up with cocktail sticks and bogies !

you mistyped "anybody from a 2 year old to a drunk tourist" ;)