If you have ever sat in the window seat of an airplane and looked closely, chances are that you may have noticed a tiny hole in the window.
Believe it or not, holes in window panes are meant to keep us safe. Known as “bleed holes”, they help regulate air pressure changes as planes climb to cruising altitudes of up to 33,000 feet.
At high altitudes, air pressure and oxygen levels reduce. To maintain comfort for passengers, cabin pressure and oxygen levels are maintained at levels higher than the surrounding atmosphere.
However, this pressure difference puts enormous strain on the windows. Don’t miss our earlier post on air pressure and airplane windows here. To help deal with the pressure, plane windows are engineered in three distinct layers.
- The inside pane that we can touch while seated inside the aircraft is only superficial
- The middle and outer panes are the layers that regulate pressure differences
- The bleed hole is in the middle pane and makes the outer pane take the strain of the low pressure outside by allowing the pressure to equalize between the passenger cabin and the air gap between the panes
Bleed holes also play another important role. They help prevent fogging. By regulating the temperature between the inside and outside, they allow us to enjoy amazing views while flying.
Even the smallest of holes have an important role to play in an aircraft and are present for a reason. Next time you are out flying, observe your surroundings. You will be amazed by the engineering behind these vehicles.