Have you ever noticed a small hole in the bottom of an airplane window?
Well, there’s a “really important” reason for that.
The pinprick hole is located at the bottom center of every airplane window, and like the every-inch hole on commercial aircraft, this hole, known as the “bleed hole,” is a highly engineered, functional design detail. .
Simply put, it’s all about pressure.
Henny Lim, a flight attendant for Philippines-based airline Cebu Pacific Air, said passengers often ask about the “mysterious” holes and whether there is a reason behind them.
“If you’ve ever sat in a window seat on a plane, you’ve probably noticed the little hole at the bottom of the window,” she said on TikTok.
“This is called the bleed hole. [It] Helps maintain pressure balance between cabin and outside air.
“Another purpose is to release moisture and prevent frost and condensation from obstructing visibility.”
When a plane reaches cruising altitude, there is a large pressure difference between the outside air and the air in the cabin, which is pressurized to mimic the lower-altitude atmosphere. Travel publication AFARreport.
Most commercial aircraft windows have an outer, middle, and inner glass, all of which are usually made of acrylic.
“The exterior windows can withstand all the stresses of cabin pressurization,” writes Robbie Gonzalez, technology writer for Gizmodo. article It’s becoming a hot topic.
The inner glass is designed to maintain cabin pressure in the “very rare” event that the outer glass breaks.
“The purpose of the breather hole near the bottom of the center glass is clear: it acts as a bleed valve, balancing the pressure of the air in the passenger compartment and the air between the outer glass and the center glass,” says Gonzalez. explained.
“This tiny little hole ensures that the cabin pressure during flight is only on the outer glass, saving the center glass in case of an emergency.”
If cabin pressure blows out the outer window (which is rare), the inner window is strong enough to hold the pressure, allowing the pilot to descend to a lower altitude and remove the inside of the cabin. This will give you time to reduce the pressure.
“by [Boeing] “According to the 737 maintenance manual, the center panel is designed to maintain 1.5 times normal operating pressure at 70 degrees Fahrenheit,” Gonzalez continued.
In other words, it is best not to touch or cover the bleed hole in order for it to work effectively.
