Why does the plane have to fly higher than Mount Everest?

Commercial airplanes often travel most of the distance at altitudes of more than 10,000 meters. Do you know why this is the ideal altitude for passenger aircraft?

One of the main reasons is that the higher the air, the more dilute the air will be, making it easier , faster, less energy efficient and saves more money.

The ideal height for passenger aircraft is from 10,000-12,800m . If the aircraft flies too high, the oxygen concentration in the air is too low, it is difficult to burn the engine, but too low the air resistance will be larger. This height is closely related to the weight of the aircraft: the heavier will fly lower, and the lighter will fly higher.

Commercial aircraft usually operate at altitudes above 10,000m.(Photo: Alamy).

The most effective way is to increase the altitude continuously, instead of flying in a straight line after reaching a height of 10,000m, because the weight of the aircraft decreases with the amount of fuel used and air density.

Peter Terry, a commercial pilot with 30 years of experience, said: 'Each aircraft has an ideal height (to get the lowest cost or fuel consumption) based on their weight. Concorde aircraft fly at much higher altitudes - from 15,200-18,200m, where other aircraft cannot be achieved '.

According to Air Canada's Captain Doug Morris, the general principle is to fly as high as possible, 'because the air is thinner, which means less drag.'

How is the weather on it?

Flying at altitudes above 10,000m means the aircraft will avoid most bad weather. You must have experienced the situation of seeing the blue sky from the airplane window, but when you came down to the airport, you saw drizzle drizzle.

The troposphere - the most near-ground atmosphere - is where most of the Earth's weather phenomenon takes place. This floor usually reaches a height of 11,000m, with clouds, heavy rain and strong winds that often appear below this level. Aircraft often operate in the stratosphere , where there is less air disturbance.

The higher the air, the cooler. If the temperature on the ground is 20 degrees Celsius, the temperature at 10,000m will be about -54 degrees Celsius.

Planes often fly in the stratosphere.(Photo: Miguel Claro).

Avoid 'traffic jams'

High flying also helps commercial aircraft avoid other aerial vehicles, such as light aircraft or helicopters, as well as insects and birds.

Light aircraft without turbocharged cabins cannot fly over 3,000m. Beyond this limit, the pilot will have to wear an oxygen mask to keep awake.

Precautions for emergencies

When a problem occurs with an aircraft at 10,000m altitude, such as an engine stopping for example, the pilot will have more time to handle the problem than if the plane is only 3,000m high. Aircraft can still land safely when both engines fail. So having time to prepare and do that can save many lives.

What is the minimum height?

Minimum safety elevation (LSALT) is applied by airline organizations around the world, including the UK Civil Aviation Administration (CAA) and the US Federal Aviation Administration (FAA).

CAA's Richard Taylor said: 'This number is applied to machines or light rather than passenger aircraft. However, the law stipulates that it cannot fly under 300m after leaving the elevation zone, or 150m on people, vehicles and works . This involves environmental reasons, such as noise, rather than safety reasons. '

The aircraft is not allowed to fly below 300 m above the highest fixed object on the ground, and the pilot must ensure that he has enough altitude to exit the crowded area in the event of an engine failure. Of course, this law does not apply during takeoff and landing, when the aircraft is in a controlled flight.

Maximum height

There are no rules for maximum altitude for aircraft. However, the engine will work harder when the oxygen level decreases, and contacting the ground becomes a challenge.

The record height of a jet achieved 37,648 m, created by Alexandr Fedotov in 1997 on a MiG-25M. The record height of a paper plane is 27,307 m (released from the helium balloon).