Sunday, 14 December 2014

Aeroplanes by Gokul Balaji 7C


Table of Contents

1-           Introduction

2-           Birth of the Aeroplane

3-           Parts of a Plane

4-           Aerodynamics

5-           Top 5 Worst Disasters of Aviation History

 
Introduction

Planes have been around for only 2 centuries, but the dream of flying has been around ever since mankind existed! Planes are fascinating modern flying machines that we see very often. They allow us to travel around world in 24 hours and furthermore, provide us with a modern, tactical, stealth, army fighting technique (Air force). However, the modern machines we see today weren’t the same throughout the time they evolved. Let’s take a look at the birth of the aeroplane.

 

Birth of the Aeroplane

Long before airplanes were of existence people used machines with flapping wings called ornithopters. The concept of this machine was developed by Leonardo Da Vinci. The problem was it worked better at bird scale rather than human scale plus a machine attached to it. Thus, people looked for alternate ways to fly.

In 1783, aeronauts made risky flights in lighter-than-air balloons, either filled with hot air or hydrogen. However this wasn’t an efficient way of flying as the wind would have to be in your favour to go in the desired direction.

In 1799, Sir George Caley developed the concept of the airplane, a controllable fixed wing aircraft.

In 1874, Felix duTemple made the first attempt at powered flight by hopping from a ramp in a steam-driven monoplane. Unfortunately, his flight was unsuccessful.

Finally, in 1894, Sir Hiram Maxim made a successful take-off in a biplane test-rig. However the flight was uncontrollable.

At the same time, Otto Lilienthal developed the first controlled flight. He had made a small glider in which you could shift your weight to steer. Inspired by his success, the Wright Brothers began experimenting with aerodynamics. Soon their work led them to building the first controllable, sustained, powered flight in 1903.

Now, planes are much more developed and safe. However, very, very rarely, accidents still happen. Let’s take a deeper look at the modern aeroplane. 

  

Parts of a Plane

Every single component of a plane is crucial. If one is not working, the plane will crash. Let’s examine the plane and its features.

 Fuselage                                                                                        
The main body of a plane, which is often long and thin with a pointed nose and has a smooth shape to cut through the air, is called the fuselage. At the front of the fuselage is the cockpit/flight deck, where the pilot controls the plane, and the rest is normally a cabin for passengers and crew. Under the cabin is a hold to store the passenger’s luggage or cargo.

Wings                                                                                                  
The wings keep the plane sky high. They stick out on either side of the fuselage, just as birds wings would stick out on either side of its body. The wings have a curved shape and we will discuss why in the next chapter. The fuel tanks are stored in the wings and the engines are attached to the underside of them. There are moving parts along the front and back edges called control surfaces, which can be tilted up or down for climbing or diving.

Tail                                                                                                     
 At the back of the fuselage is a tail, which gives the plane stability. It looks like a shark’s fin with two small wings on either side, which help the plane stop swaying from side to side. Control surfaces located on the small wings called elevators can be tilted up or down to ascend or descend and control surfaces called rudders can be moved from side to side to steer the plane.

Wheels                                                                                     Obviously, planes need wheels to move on the ground to get to their runway; planes have wheels attached to the underside of the fuselage. The wheels of a plane are large (small compared to the plane) and strong, as they need to carry huge planes on their shoulders which can weigh up to 640 tonnes! The heavier the plane the more wheels it needs to smoothen the landing ; the Antonov An-225, used to transport planes and shuttles, is the world’s largest and heaviest aircraft weighing a massive 250 tonnes when empty and up to 640 tonnes when loaded! The An-225 has an unimaginable 32 wheel landing gear system!


Engines                                                                                             
One of the most crucial parts of a plane is the engines, which provide thrust and keep the plane moving. If you blow a balloon and then let it go without tying the end, the balloon will shoot away as the air rushes out of the opening; in the same way, when gases rush out of the engine, the plane moves forward. Some small aeroplanes have one but most modern aeroplanes have at least two. A plane is designed such that if one engine malfunctions, a very unlikely occurrence, it can go on with the other engines, and undertake an emergency landing. There are two main types of engines, turbofan and turbojet. How do they work?

Turbojet: A turbojet engine uses spinning blades called a compressor to suck air into the front of the engine and squeeze it tightly. As fuel needs air to burn, the air mixes with the fuel. Hot gases created by the burning fuel shoot out of a nozzle at the back of the engine, thrusting the plane forward. These engines are used in fighter planes.

Turbofan: A turbofan engine, if you couldn’t tell from the name, uses a large fan at the front to suck in air. Unlike the turbojet engine, not all the air is squeezed and burnt with the fuel, some air goes around the outside and mixes with the hot gases. These engines are seen in most modern airliners, as they make less sound compared to a turbojet, and are cheaper to run.

Now we know the parts of a plane. But, this is only one component that leads to successful flight of an aircraft. Now, we’ll take a look at the second component, which a simple mechanic by the name of aerodynamics!

Aerodynamics

A lot of thought was put into the concept of the aeroplane, and there is a lot more to a plane’s flight than just the engines. There are certain forces and mechanics that allow a plane to fly. What are these mechanics you ask? Let’s take a look!

Firstly, planes work on fluid mechanics. There are different fluids in the air which we can use to our advantage and at the same time could work against us. There are four forces which are associated with a plane’s flight: Drag, Thrust, Weight and Lift. What are they?

Drag, caused by fluids in the air, is the force that resists motion. This slows the plane down. How does a plane oppose this force and move?

Thrust, often produced by an engine, is the force that pushes or pulls the plane forward. If there is not enough thrust to counter the drag, the plane will go into a stall, and crash.

Weight, caused by the Earth’s gravitational pull, is the force that pulls the plane down. How does the plane oppose this force, and stay in the air?

Lift, the opposing force of weight, is the force that pushes the plane upward. This is done through a simple mechanic of the wing. When the plane is flying forward, the wing cuts the air it counters into to two flows of air, one flowing above the wing, and flowing below the wing. As the wing has a curved shape, the flow above’s path narrows and the flow bellow’s path widens, thus, the air above flows quicker, due to all molecules rushing through the narrow path, than that of the air below. According to Bernoulli’s theory, the quicker air moves, the less pressure it exerts. Therefore, the air above the wing is exerting less force than the air bellow resulting in an upward lift force.   

Now you know a lot more about planes, and it will be easier to understand why these crashes happen and how they happen very rarely. Ok, enough jibber jabber, let’s get straight into the TOP 5 WORST DISASTERS OF AVIATION HISTORY

 TOP 5 Worst Disasters of Aviation History

Just to clarify, these are very rare occurrences and will not happen to you. If you are extremely sensitive, this section may not be for you. But, if you are eager and intrigued by mysterious and unusual occurrences, here are the top 5 worst disasters of aviation history!

5-Ermenonville Air Disaster- 346 dead

On 3rd March, 1974, Turkish Airlines Flight 981 crashed into Ermenonville forest near Paris, France after a  Moroccan baggage handler couldn’t read the latching instructions, which was written either in Turkish or English, and improperly secured the latches of a cargo door which blasted off causing explosive decompression which severed cables necessary to control the plane.

4-Charkhi Dadri mid-air collision- 349 dead

On 12th November, 1996, Saudi Arabian airlines and Kazakhstan airlines crashed just west of New Delhi killing everyone on both planes. The incident was again due to lack of English skills on the behalf of the Kazakh pilots. This was the most deadliest mid-air collision of aviation history.

 

3- Japan Airlines 123- 520 dead

On 12th August, 1985 Japan Airlines 123 flying from Tokyo to Osaka crashed into Mount Takamagahara. The plane lost stability due to problems with the tail. Surprisingly, there were 4 survivors.

2-Tenerife Airport Disaster-583

On March 27, 1977, KLM Flight 4805 and Pan Am Flight 1736 collided with each other on a runway in airport of Spanish Island, Tenerife, one of the Canary Islands. The crash was caused due to the impatient pilot of the KLM as he began to speed up on the runway of which the Pan Am was meant to take off first.

1-   9/11 Flights

On September 11, 2001, although not a single air disaster, the four flights involved in 9/11 were responsible for the greatest single day loss of life in commercial aviation history. Two of the flights, American Airlines Flight 11 and United Airlines Flight 175 each were responsible for thousands of casualties after being driven into the World Trade Centres and are considered the largest and second largest losses of life due to individual plane crashes in all of aviation history with 1700 and 1000 people killed respectively.

To conclude this article, planes are amazing creations. However, they can be dangerous and deadly. Then again, these are very rare occurrences and the odds of an accident occurring is one in 1.2 million and the odds of dying in a plane accident is 1 in 11 million. Additionally, most of these disasters happened before 2000, and security and safety in today’s airports have undertaken a dramatic change. Thus, there is no need to worry.

 Bibliography


en.wikipedia.org

www.wright-brothers.org

(Book) 100 Facts about Planes

                                                                        


                                                                                    

 

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