Airplane in sky

Ask the pilot: How High do planes fly?

The experts with all the answers are, of course, the pilots.

Photo: Keiko Iwabuchi
December 2022
Even the most experienced travelers have questions about the inner workings of planes. How do planes react to weather conditions? What do all the noises mean? How do they take off and land? The experts with all the answers are, of course, the pilots.

”During the flight, as the fuel is burned, the aircraft will be able to climb to a higher altitude.”

How high do planes fly? /Irina

Hi Irina,

The Boeing 737, the aircraft that I fly, has a maximum ­altitude of 41,000 feet (12,500m). This altitude has been determined by Boeing based on the characteristics of the aircraft and engines as well as on the capacity of the pressure cabin to maintain ­sufficiently high pressure. ­Different airplanes have ­different maximum altitudes, depending on their ­construction. For example, the Airbus A320 has a maximum altitude of 39,000 feet (11,900m) and the Boeing 747 45,000 feet (13,700m).

More environmentally friendly to fly at high altitude

The air gets thinner higher up as the density decreases, so air resistance is lower at higher altitudes. This means that an aircraft can fly faster and use less fuel at increased ­altitudes. Consequently, we usually strive to fly as high as possible.

When an aircraft is heavily loaded, it is often not possible to reach the optimal flight ­altitude at the beginning of the flight. This happens especially on longer flights where the aircraft initially has many tons of fuel onboard that need to be lifted. During the flight, as the fuel is burned, the aircraft will be able to climb to a higher altitude.

High flight reduces the risk of turbulence

Another advantage of flying high is that most weather phenomena, such as rain and thunderstorms, are in the troposphere (0–11,000m above ground) and flying above this reduces the risk of ­turbulence.

That said, winds can also have a significant impact on the choice of flight altitude. With a strong tailwind, for example, it can be better to fly at a lower flight altitude than would be optimal under ­zero-wind conditions.

Computer programs are used to find the optimal flight altitude for each flight.

Pernilla Nilsson
Senior First Officer


Pernilla Nilsson

Title: Senior First Officer
Home base: Copenhagen
Flies: A319, A320, A321
Flight hours: 13,500
Favorite airport: Most of the Norwegian airports. They can be very challenging in harsh weather but a beautiful day it’s unbeatable. The landscape is fantastic with the mountains and fjords. You’ll never get tired of this view.