This Is The Reason Why Commerical Airplanes Fly So High

planes fly high
Source: Reference

You might have heard people say, speed and altitude are a pilot’s best friends. We gathered a list of reasons why this is true.

Efficiency and Speed

Aircraft engines are optimized for better speeds at higher speeds and higher altitudes. At higher altitudes, density is lower. Thus the drag force on the airplane is reduced. Tailwinds at higher altitudes also give a slight boost to the aircraft speed. Hence at higher altitudes, the craft fuel efficiency is enhanced.

Noise Reduction

Even though a lot of work is being done to make the airplane engines quieter, they are still very noisy. They add significantly to the noise pollution. If flown at lower altitudes the noise pollution will be much higher. Especially considering the Supersonic Transport (SST) aircraft, which is noisier than the conventional turbofan-powered aircraft, it makes perfect sense to fly them at higher altitudes.

Weather Effects

Weather fluctuations regarding rain, clouds, and winds, at higher altitudes are much less than at the sea level. There is still some turbulence at high altitudes, but it is far worse at lower heights. Thus, for commercial airliners, the flying altitude is at least 9km.


Aircraft are tracked by Air Traffic Control using Radar. At lower altitudes, the radio communication will be interrupted by building and other high objects. It is thus difficult to track a low altitude aircraft using radar.


A very obvious reason is that the earth is not smooth everywhere. While flying at lower altitudes, mountains, rivers, forests, cities, everything will be a hindrance, and it will be very hard to avoid hitting them. The chance of bird hits at lower altitudes is also very high.

Accident Handling

In case an aircraft engine fails, pilots would have more time to recover and stabilize when at greater altitude as compared to near ground level.

Here’s how the SciShow explains all of this:

There may be plenty of more reasons, but there’s one thing we sure do know, no one wants to fly low.



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