The most common altitude on commercial flights is between 33,000 and 42,000 feet, with 36,000 feet usually being the choice of pilots.
- According to USA Today, it has to do primarily with fuel economy, as the thin air at this altitude brings less resistance to the fuselage, and so the aircraft needs less fuel to maintain its speed.
- The second reason is that at 36,000 feet you avoid birds, drones, and helicopters, which fly lower. Routes flying in the same direction are at least 1,000 feet apart to avoid collisions.
- The third reason is the weather. All meteorological phenomena take place in the troposphere, which is below the stratosphere. That is why commercial flights are avoided and they prefer the lower parts of the stratosphere.
- The fourth reason is the turbulence, as it is weaker as the altitude increases.
- Finally, the high altitude offers pilots a “luxury”: Time. If, for example, an emergency landing or on-the-spot repair is needed, the time frame is much longer than if the plane were flying at 10,000 feet.