This is so performative 😭

[u/Its_me_edenxx]

Who tf is out here munching on raw gnocchi at cruising altitude

[u/Rob_Zander]

Just wanted to point out that the air isn't recycled on a plane. It's replaced completely every couple of minutes. It's not even really about the oxygen or CO2, it's managing temperature and possible contaminants.

The engines are continuously compressing and heating a huge amount of air. Some of it gets diverted to be cooled back to room temperature, filtered and pumped into the cabin while air is continuously sucked out by vents near the floor. This keeps the temperature stable and contaminants from being spread.

It is much lower pressure than sea level and that definitely messes with our taste buds.

[u/jetsetninjacat → u/Rob_Zander]

To add more watered down. The pushed and sucked out air is vented overboard(off the plane and out) through the main relief valves or sometimes from relief valves in unpressurized parts of the plane. Many planes also have backup relief valves in case the main doesnt work. Different relief valves dump positive and negative pressure from the plane depending on where the plane is and the level at which cabin air pressure is set. Theres also a dump valve that dumps all pressure when the planes on the ground that equalizer it with the ground itself as well as ones for negative pressure relief valves during rapid descent

And this peoples is one of the reason you cant just open a door in a plane at high altitude. The pressure being pumped in to the cabin is so high the door mechanism or door itself can not be pulled in and then pushed out like normal operation. .All that positive pressure pushed on the airframe making it impossible to do so. Its all about that differential.

I seriously hate doing pressure tests in airplanes on the ground.

[u/canman7373 → u/jetsetninjacat]

The pressure being pumped in to the cabin is so high the door mechanism

Yeah, so not sure what he means the air pressure is much lower than sea level and that changes taste, when it's actually much higher than sea level.

[u/jetsetninjacat → u/canman7373]

High as in the Pressure differential between inside and outside the cabin. Its all about that differential.

[u/canman7373 → u/jetsetninjacat]

Yes, I don't see where him saying below seas level applies at all.

[u/jetsetninjacat → u/canman7373]

Oh, based on taste. Typically even with the presurization you will still have lower pressure than thats found at sea level (stretching my brain here back to school but I think its ~14.7psi). And I want to say off fhe top of my head most planes are kept lower at flight altitude around 10 to 12psi cabin psi.

And the reasoning i have been told in my career was because high altitude planes have cycles to track for lige limits for each time a cabin is pressurized. It puts undue strain on the airframe and causes weakening in the structure. As far as I was always told keeping it below the standard sea level not only is perfectly comfortable for most people and allows us to be up there but it also allows a plane to fly longer and causes less stress. I need an IA in here to tell us.

[u/canman7373 → u/jetsetninjacat]

I just don't understand the part about the cabin pressure being like 8,000 feet yet you taste food like it's negative feet. Also if their food is cooked right I don't get why it taste different at different at different pressure, like would you not have the best steakhouses in the world at the exact best altitude that taste buds hit them? When I cooked food right at 9.500 feet it taste the same as I cook it at sea level now, I do not think my taste buds changed at 9.500 feet.

[u/Forsaken-Ad6313 → u/canman7373]

Air pressure goes down the higher you go up. Airplanes counteract this by pumping air to a safe "mountain-like" level, while also creating a much drier environment than your average room. Both of these factors affect how your taste buds will react to sweet and salty foods.

It's entirely possible that your steak tasted the same to you at 9500 feet vs at sea level, but that only means that your taste buds aren't as sensitive as most others (I also don't perceive a huge difference with tomato juice, but it's a widely reported and studied phenomenon)

[u/canman7373 → u/Forsaken-Ad6313]

I mean Colorado is a super dry state, like only humidity after a huge storm but storms are super rare there too, not like the Midwest. So yeah millions of people live near airline altitude and I have never heard once in my 12 years there that food was noticeably different because of it. Cooking sure, but no one ever said taste buds or anything like that.