The cargo bay of a plane is where your bags and other cargo are stored. Planes are designed so that your luggage and everything in your bags stay safe when they are thousands of feet in the air.
But what about the pressure surrounding your luggage? Is the cargo bay of a plane pressurized?
The cargo bay of a plane is pressurized. The pressure when we fly at thousands of feet in the air is too high for us to survive in, much less the items we put in the cargo bay. We must pressurize the cargo bay to keep these items safe during the flight.
Imagine arriving at your destination after a long flight and opening your bag just to find that your shampoo and toothpaste exploded all over your clothes in your bag. It would ruin your trip, right? Well, that would be a constant occurrence if we put our bags in an unpressurized cargo bay.
This article explains why a plane’s cargo bay must be pressurized. Then I explain whether or not the main cabin of an airplane is also pressurized.
Why Are Cargo Bays Pressurized?
The cargo bay of a plane has to be pressurized. Otherwise, the pressure would destroy everything we put in there during the flight.
For example, if you pack a bottle of wine in your checked luggage, it will arrive at your destination safely. But, the bottle would explode if the cargo bay was not pressurized.
This risk of destruction is true of everything we pack in our checked bags, including medicine, bathroom items, and more. If we left them in an unpressurized area, the pressure would destroy everything, and your vacation would be ruined.
Sometimes airlines even put pets in a cargo hold. If you are flying with your pet, and they cannot fit under the seat in a carrier, they will have to go elsewhere on a plane. Usually, they end up in the cargo bay of the plane.
But, if the cargo bay was not pressurized, the pets who fly in them would not make it through the flight. That is the last thing we want to happen, so we can keep our pets safe by pressurizing the cargo bay.
In addition to being pressurized, airplane cargo bays are also cold. Without a temperature-controlled cargo bay, all our belongings would be destroyed by extreme temperatures, similar to in a non-pressurized cabin.
Is the Main Cabin of a Plane Also Pressurized?
Similar to the cargo bay of a plane, the main cabin is also pressurized. The main cabin of an airplane is where we sit throughout the flight.
When the plane is still sitting on the ground, everything is depressurized. But, before takeoff, the pilot has to pressurize the plane.
The pressure in the cabin when we are flying high in the air is equal to the pressure we would feel at around 8,000 feet.
To maintain the pressure in the cabin equal to that at low altitude, even while the airplane is at 30,000 feet, the incoming air is held within the cabin by opening and closing an outflow valve, which releases the incoming air at a rate regulated by pressure sensors.
As I mentioned above, one of the reasons the cargo bay needs to be pressurized is for any pets who are in them. Like the pets, we need to breathe during the flight, so we also need the main cabin to be pressurized.
If we are up in the air and the pressure changes too fast, our bodies will try and compensate, and the air within our bloodstreams will expand. If our blood streams expand too much, they will burst and die, which is why we need the pressurized cabin in the air.
Passengers actually flew in an unpressurized cabin on a Jet Airways flight. The pilot forgot to pressurize the cabin before taking off. Passengers started getting bloody noses as a result of the change in pressure, and the flight had to make an emergency landing.
Everyone on the flight was safe, but it shows just how dangerous it could be for us to fly without a pressurized cabin.
Furthermore, the main cabin and cargo bay must be pressurized. If the pilot pressurized only one of them during the flight, they would start to destroy the wall between them from the pressure difference. Having two different pressures would cause major safety problems, and the plane would start to change shape.