Planes can't fly too high because the air gets thinner as you ascend, making it difficult for engines to generate enough thrust and for wings to produce lift.
- Thin Air: At high altitudes, the air density decreases significantly. This means there are fewer air molecules for the plane's engines to "breathe" and for the wings to push against.
- Engine Performance: As the air thins, jet engines struggle to draw in enough oxygen to burn fuel efficiently. This results in reduced thrust, making it impossible to maintain altitude or climb further.
- Lift: Wings rely on the pressure difference between the top and bottom surfaces to create lift. At high altitudes, the thinner air reduces this pressure difference, making it harder for the wings to generate enough lift to stay airborne.
Coffin Corner: A particularly dangerous point in high altitude flying is called "Coffin Corner," where the aircraft's stall speed and its high-speed buffet (a violent shaking caused by turbulent airflow) become dangerously close. This makes it extremely difficult to control the plane.
Other Factors: Aside from the air density issue, planes also have structural limitations and operational considerations that restrict their maximum altitude:
- Structural Limits: Planes are designed to withstand specific pressure differences between the inside and outside. Exceeding the design limits could lead to structural failure.
- Oxygen Deprivation: At extreme heights, the air is too thin for humans to breathe. Pilots must rely on supplemental oxygen systems.
- Regulations: Airlines and aviation authorities have strict regulations on maximum operating altitudes to ensure safety and prevent potential risks.
In essence, planes have a practical altitude limit because of the limitations imposed by air density, engine performance, and aerodynamic principles. Beyond this point, it becomes impossible for the aircraft to maintain lift and stable flight.
