Here's The Reason There Are Little Holes In Aeroplane Windows

Have you ever been on a plane and wondered "what are the little holes in the windows for?"

Well thanks to Robbie Gonzalez from io9, we might have an answer!

It turns out that Robbie found a maintenance manual of the Boeing 737 via Wikileaks before ensuring that he contacted the correct people in order to get an accurate description on what he was viewing.

Essentially, it’s to do with the regulating pressure.

The majority of cabin windows have inner, outer and middle panes & surprisingly only the two latter are structural, with all of them being created from synthetic resin. The thing to bare in mind is that the amount of pressure in a plane usually lies at an artificially-maintained 3.5 kilograms per square inch.

The holes are required to be there in order to maintain cabin pressure in the event of the outer pane receiving a fracture. The outer pate is the thickest, and it’s technically the proverbial glue that holds the pressure of the cabin together.

According to Gonzalez himself the hole is there to “act as a bleed valve, allowing pressure between the air in the passenger cabin and the air between the outer and middle panes to equilibrate”.

To summarise the little hole, it makes sure that the outer pane can bare the pressure which allows the middle pane to be available in the case of an emergency.

Source.