❓ why
Why do airplane windows have tiny holes?
aviationengineering
Quick Answer
The tiny 'breather hole' balances air pressure between window panes so the strong outer pane carries the load, and it stops the window fogging.
The Full Story
Airliner windows usually have three panes. The outer pane takes the pressure difference between the pressurised cabin and thin outside air, while the middle pane is a fail-safe backup. The small bleed hole in the middle pane lets air pass so the middle pane stays unstressed unless the outer pane fails. It also lets moisture escape, so frost and fog do not build up between panes. The innermost thin pane is simply a scratch shield for passengers.
Key Facts
1.Most airliner windows have three layers of acrylic.
2.The breather hole is usually found in the middle pane, near the bottom.
3.Cabins are typically pressurised to the equivalent of 1,800–2,400 m (6,000–8,000 ft) altitude.
YouTube Angle
Suggested video title for this topic:
"The Tiny Hole in Every Plane Window — Explained"