Humans were designed to stay very close to the ground and live in the paper-thin layer of oxygen, nitrogen and other gasses that we happily call “the atmosphere.”
This apple skin thick layer of breathable gas that we pilots have become accustomed to sucking into our lungs at a partial pressure of somewhere around thirty inches of mercury, or 14.7 psi, is used by aircraft more efficiently the higher they can climb.
Airplanes, especially business and charter aircraft perform better and can cavort happier through the upper levels of the Troposphere where the air is thin but the true airspeeds and tailwinds can amaze and result in high-speed travel.
We low level humanoids don’t do very well in terms of staying alive if we have to breathe the air that is available above somewhere around eighteen thousand feet. To be specific; the same thin air that our aircraft love and thrive in would kill us humans in very short order if we don’t get some help.
Pressurization has been around since the 1920s. Wiley Post, the eye patch wearing buddy to Will Rogers and high altitude record setter, used a pressurized flight suit in his aircraft on December 7, 1934 when he set an unofficial record by flying the single engine aircraft to an estimated fifty thousand feet. Without pressurization, Post’s blood would have boiled and he would have died in a few seconds at that altitude.
The electronics and gizmos that control the pressure in your aircraft can’t talk …