Page 42 - World Airnews Magazine April 2020 Edition

FEATURE

SEVEN FACTS THAT WILL

OPEN YOUR EYES

By Gediminas Ziemelis

long answer would involve an in-depth Avoiding traffic and other hazards are other

explanation, terms and formulas, but reasons. Usually this traffic consists of light

viation is amongst the greatest there is a simplified answer. As the plane aircraft, helicopters, drones and even birds.

Aachievements in the modern flies, fast-moving air enters the jet turbine All of which can be avoided by flying higher.

human history. It connects the world and engines located on the wings of the plane. Moreover, flying at that high level pro-

pushes globalisation by allowing people The air is compressed as it passes through vides pilots with time in the case of emer-

to travel around the world and delivering the blades of the engine, however, at this gencies, where they might need to find a

cargo in short periods of time. stage, the temperature of the air could solution for a certain situation or prepare
Airplanes themselves are marvels of reach almost 100 degrees Celsius. There- for an emergency landing.
engineering, showing how far humanity has fore, it has to go through a heat exchang- AIRPLANE TYRES ARE NOT FILLED
come and how much it has achieved. There er, which cools it down to a comfortable WITH AIR

are countless facts about aviation and temperature for inhalation. Finally, the

airplanes themselves, most of which are cooled and filtered air is dispersed into the This might be a bit surprising and
related to the science and engineering of passenger cabin. unusual, but airplane tyres are inflated by

planes and the way they operate. However, Additionally, an outflow valve, which is nitrogen rather than oxygen to prevent
vast amounts of people are not really inter- usually located at the back of the cabin, them from catching fire and exploding

ested in that, instead they are keen to find makes sure that the used air is vented out, during landings.

answers to some common questions. and so the air in the cabin is always fresh. The tyres on an airplane face an
Here are seven statements of fact and HOW HIGH DO AIRPLANES FLY incredible amount of pressure during
common questions about aviation industry AND WHY? landings due to braking and high speed.

that you may have been wondering about. As a result, they reach incredibly high

As mentioned earlier, the optimal altitude temperatures, so the oxygen inside the
HOW DO WE GET BREATHABLE AIR ON or ‘sweet spot’ for commercial airplanes to tyres would react with the heat resulting
AN AIRPLANE? cruise at is between 10 and 12 kilometres in an explosive fire outburst. Nitrogen, on
Have you ever asked yourself where is the and there are several reasons for that. the other hand, is an inert gas and does

breathable air coming from when you are One of the main ones is fuel efficiency. not react with the rubber inside the tyre,

flying in an airplane? At that altitude the air in the atmosphere is making it much safer.

A modern commercial airplane cruises very thin, this means there is less resis- A SECRET: THIRD ENGINE ON AN
from approximately 10 to 12 kilometres, tance for the airplane to pass through. As AIRPLANE.

which is considered the ‘sweet spot’ or a result, the airplane needs less effort to

good level to fly at (more on that later). At maintain the speed, thus using less fuel. Commercial aircrafts usually have two engines

that altitude, the supply of air is not a prob- But what would happen if airplanes flew on each wing; bigger aircraft might have four

lem; there is actually enough of it. How- at a higher altitude would they get less engines. However, very few people know that
ever, the issue is that it is not a breathable resistance? At that point, it would create each airplane has one, much smaller engine
air as the pressure of the oxygen in it is too problems for the engines as they need oxy- in the tail of the airplane, which ensures the
low to be directly inhaled by humans. gen to work, which is very sparse at higher smooth running of the plane.

So, how do we actually get fresh, altitudes and there is not sufficient levels The engine is called the auxiliary power

breathable air when flying? Of course, the for the engines to operate properly. unit (APU). Even though it does not help to
World Airnews | April 2020
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