For most commercial aircraft, operations are carried out at an average altitude of around 33,000 to 42,000 feet above sea level. At this height, modern engines can perform optimally and with the benefit of avoiding common adverse meteorological conditions. Despite these advantages, oxygen conditions at such heights are not suitable for breathing, making it essential that passengers, pilots, and crewmembers are offered an atmosphere that is safe and comfortable. To do this, cabins are sealed, pressurized, and supplied with a stream of breathable air. In this blog, we will discuss the process of air circulation for commercial aircraft, allowing you to better understand how such environments are established and upheld.