The Science Behind: Airplanes
COVER PAGE - Ishita Aggarwal
I am sure that almost all of you have been on an airplane, enjoying the view and the comfort of reaching your destination in good time. But have you ever wondered how an airplane works? When I was a kid, I used to think that airplanes were heavy since they carried so many people. But later, I got to know that they are actually made so that they are light even with all the passengers. How is this so?
First, how are planes designed?
There are 4 forces acting upon an airplane:-
1] WEIGHT- acting towards the center of the earth
2]LIFT- acting perpendicular to the direction of motion
3]THRUST- acting along the direction of motion
4]DRAG- acting opposite to the direction of motion
The engines of a plane are designed to move it forward at a very high speed which makes the airflow rapidly over the wings. Due to their shape (called an airfoil), they throw the air down towards the ground, generating an upward force called lift. When the force of the lift is greater than that of gravity, the airplane is able to fly. Because of the thrust, the plane is able to continue moving forward in flight.
All planes today are made up of aluminum. Since aluminum is a strong and light metal, it reduces the total weight of the airplane. The less weight an airplane has, the fewer work engines have to do. Therefore, the plane uses less fuel. Each and every bit of weight saved in construction helps the company make more money, as more luggage can be carried.
Why are airplanes usually painted in light colors?
The reason why an aircraft is painted in white or light colors is to reflect sunlight. Dark colors absorb sunlight and make the body of the plane hot, which isn’t favorable, as aluminum heats up rapidly. Also, by keeping the body of the airplane cool, light colors keep the cabin cool as well.
What does the word “autopilot” mean? How does it work?
Autopilot isn't as "auto" as you might think. There's no robot that sits in the pilot seat and smashes buttons while the real pilot takes a nap. Autopilot is a flight control system that is used to guide an aircraft without direct conscious control of the pilot. This system works by sending signals to the flight control systems, and the pilot inputs what kind of model they want. Planes can be successfully landed by using the autopilot system. The pilots can program the autopilot to carry out the landing automatically. Automatic landings account for less than 1% of all landings on commercial flights.
How are planes similar to birds?
People have looked up at birds for many years, as they're the ones who inspired us to fly.
1] Airplanes have wings just like birds.
2] Their bodies have a light structural framework. This means that they have hollow bones that are filled with air. It is thought that this structure helps with oxygen intake during flights. They also have a streamlined shape to decrease the drag.
However, unlike birds, planes are designed to create lift by changing pressure, rather than flapping their wings up and down.
Why can’t humans fly?
According to an article in Yale Scientific, “It is mathematically impossible for humans to fly like birds.” The first reason is that the span and strength of a bird’s wings are in balance with its body. Secondly, birds mostly have hollow bones which make them light in weight and provide air pockets to give them more oxygen while flying. It is not because we are too big or too weak that we can’t fly. Instead, it is because we would need bigger wings. As an organism grows, its weight increases at a faster rate than its strength. An average adult male would need a wingspan of at least 6.7 meters to fly. But bigger wings mean more mass, which would make the human body even heavier. Giving humans working wings would not just mean extra appendages—we would have to redesign the human body from the ground up.
Until next time,
Keep wondering;)
Love,
Shruti
https://www.grc.nasa.gov/www/k-12/airplane/forces.html
https://www.nasa.gov/sites/default/files/atoms/files/bernoulli_principle_k-4.pdf
http://www.yalescientific.org/2013/03/qa-why-cant-humans-fly/
https://soar.edu.au/blog/why-humans-cant-fly-aerodynamics-explained/