In this guide, we will discuss the history of aviation and the scientific work that was needed to get the first manned plane airborne!
Today, flying a light aircraft may seem like an easy task that involves going at high speeds and using the controls in the aircraft to fly with the wind. However, there is quite a lot of science, specifically, physics that goes into getting an aircraft airborne.
To understand the physics of flying, we will have to start from the beginning and see how science and engineering helped humanity reach the skies – literally.
In this guide, we will discuss the history of aviation and the scientific work that was needed to get the first manned plane airborne!
Flying – From Fiction to Reality
Humans have been dreaming of flying since the early days of man. It is believed that humanity thought about flying as early as the 4th century, and there are even Greek legends, like that of Daedalus that go back even before that time. In the legend, Daedalus fastens together feathers and straps them on a rigid wooden skeleton using thread and wax. He then uses his contraption to soar through the skies – not unlike the very early designs of aircraft!
The truth is, humanity looked at birds as an inspiration for flying. Many mathematicians, philosophers, and early inventors pondered upon the idea of flight and took to nature for inspiration. Birds seemed like the best bet because all of them used the same mechanism to fly, but of course, we had a lot more to learn before we could even fathom designing something similar to an aircraft.
The earliest designs of aircraft were more focused on vertical flying since most flying machines were built on the idea of using hot air to achieve lift. However, this poses an even more interesting question: how did we achieve flight using nothing but hot air?
Ever seen party balloons that rise and annoyingly get stuck to the ceiling? That happens due to the balloons being filled with helium, which is lighter than air – but in the case of hot air balloons, these machines weigh hundreds of kilograms, and yet they can float using the same air that you breathe.
The reason why hot air balloons can fly is because they use hot air, which is less dense. To understand this concept, we need to break it down using physics. When a molecule is at rest, it doesn’t move around much. Take the example of water: when water is at room temperature, you see a smooth and even surface that sits undisturbed; but when you heat it, it begins to boil and the water begins to condense into steam. This happens because we are adding energy to the water molecules and “exciting” them.
When a molecule excites, it vibrates, and the more energy you put into it, the more it vibrates and moves. This is exactly how the water molecules in a boiling pot of water escape! We can apply the same concept to air as well. After all, the air is made up of billions of air molecules.
When we heat air in an enclosed space, the air molecules vibrate and eventually escape through the bottom of the balloon. Now this is where hot air balloons and light aircraft share the same concept of physics: air maintains a certain pressure called atmospheric pressure. In fact, as you read this article, the air is pressing down on you at a constant rate.
When there are a lot of air molecules in any given space, the pressure increases, and when you take away the air molecules, the pressure decreases. This is why air pressure is different at sea level and above the stratosphere!
So, by heating the air, we create a less dense and low-pressure zone inside the balloon which causes the molecules to be farther apart than the air outside of the balloon. This, along with the air around the balloon with more pressure exert a force that allows the balloon to lift.
While it is widely accepted that humanity owes flying to the Wright brothers, it was the hot air balloon, designed by the Montgolfier brothers in the 16th century that should get the credit for the first flight!
Combining Clever Engineering and Science
Hot air balloons not only allowed us to float in the air, but they also unlocked our understanding of what air really is. Scientists started to consider air as a fluid, just like water. Daniel Bernoulli, a Swiss physicist, helped paved the way for our advanced understanding of air, which eventually lead to the development of a new field of science called aerodynamics.
We will get to aerodynamics in a bit, let’s first talk about Bernoulli, who provided us with an incredibly important piece of the puzzle of flight.
Bernoulli discovered that air acted just like water and its flow could be “manipulated” by using mathematically precise designs. For example, if you add a flow to a body of water/air and put a piece of curved material along the flow, you will see that the water curves around the material and creates a pressure difference too.
Bernoulli stipulated that when air crosses at high speeds and is intercepted at a certain angled body, it can create a pressure difference above and below the body. Take the example of an aircraft’s wing.
The wing is designed to cut through air like a knife, but it is positioned in a special way where air runs quickly above the surface and slightly slowly below the wing. When air moves quickly, it creates low pressure above the wing, while slow-moving air exerts more pressure from below the wing. This pressure difference, along with the speed of the plane and its control surfaces is what allows light aircraft to achieve lift.
An easy way and fun way to visualise this phenomenon is to conduct a simple experiment at home. Take a small piece of paper and hold it away from your mouth in a way that the other end limps downwards. Now blow air above the paper. You will notice that despite blowing above, the paper rises from below. This is Bernoulli's principle in action!
So, when we combine this physics concept with engineering, we can create a highly efficient wing system designed at just the right angle to displace air in a certain way to achieve flight – and this is exactly what scientists and engineers did between the 16th and 20th centuries!
The only reason we didn’t crack the code of flight before the 20th century was that we lacked material knowledge and were still dependent on large and clunky steam engines that were too heavy to be used in aircraft designs.
Of course, that is until the late 1800s and early 1900s! By then, we had the basis of the combustible engine that provided power efficiently while taking up less space. We also were able to build more precise and contoured designs using sturdy materials. The combination of these things is what led humanity to the moment at Kitty Hawk, North Carolina when the Wright brothers unveiled and successfully flew the first-ever manned aircraft in human history.
Understanding How Light Aircraft Work
Light aircraft are the cumulation of the concept behind hot air balloons and the scientific progress in the field of aerodynamics. Modern aerodynamic concepts include subtopics such as lift, drag, thrust, take-off weight, etc.
Let’s quickly explore these concepts and explain their role in making light aircraft fly:
Aerodynamics
As explained above, aerodynamics is the study of how air interacts with solid objects when in motion or when stationary. Aerodynamics is an incredibly important concept that helps engineers and scientists in not just aircraft, but in building anything that interacts with high-speed air, even skyscrapers!
The study of aerodynamics is what led engineers to build highly efficient and effective propellors and wing systems. In fact, aerodynamics is specifically covered in pilot training so that pilots have a full understanding of how their aircraft flies and how not to manoeuvre it to keep it safe while in the air.
Lift
In simple words, lift is the upward force that allows an aircraft to fly. Take the Bernoulli effect: when air moves quickly above the wing, it creates a low-pressure zone while the high pressure at the bottom pushes the wing upward, creating lift.
Lift is an equally important concept to understand because it allows the aircraft to counter its weight and fly. As you can imagine, lift and aerodynamics are closely interlinked since modern planes use a series of “tricks” that go beyond the simple Bernoulli effect to manipulate the air to push the aircraft upward.
For example, when travelling at high speed over the runway, the pilot also engages the flaps located at the tail wings. This moves air in such a way that the tail of the aircraft is pushed downward, lifting the nose of the plane even more. This manipulation along with the Bernoulli effect is what makes the plane fly up so effortlessly!
Drag
You might have heard of drag when talking about fast-moving cars. Well, the same concept applies to aeroplanes as well!
In simple terms, drag is the resistance caused by the moving air when the plane flies. Want to experience drag in real life? Simply put your hand out of a moving car and open your palm. You will immediately notice the air pushing back on your hand due to the resistance it is causing. Drag is important to understand because conquering it can not only increase efficiency but can also allow planes to fly faster and more effectively.
Thrust
Thrust is power. In other words, it is what propels the plane forward and what eventually causes it to fly. Thrust is generated by engines. For example, the combustible engine used in the first-ever manned airplane by the Wright brothers allowed them to propel the plane forward at high speed which allowed more air to pass through the aerodynamic wings.
The higher the speed, the more pronounced the Bernoulli effect! The quicker the air passes through the top of the wing, the more low-pressure it will become which will cause the upward force from below to push the plane up. You can see thrust in action just before taking off on a passenger plane.
After the final pre-flight checks, the stationary plane starts to move along the runway, and suddenly, it is pushed at very high speeds using the turbo engines on each wing. Thrust initiates all the phenomena that we have discussed above.
The engines use a physics concept too, specifically Newton's third law of motion. As the engines expel a stream of air in the opposite direction, it causes an equal push forward which generates thrust and propels the plane.
Take-off Weight
Finally, the last thing that a light aircraft needs to overcome is gravity. Gravity pulls down on objects and the more they weigh, the more power and lift they will require to achieve flight.
Light aircraft weigh significantly less than passenger planes that can weigh thousands of kilograms. However, light aircraft also usually use a single and relatively low-powered engine which is why they need to be kept under their maximum take-off weight (TOW) to achieve flight.
You can also look at this as an equation where the lift that a plane generates must be equal to the weight of the plane. Think about it, if you try to fly a plane that weighs more then you will end up with essentially a funny-looking car that can only travel forward without achieving flight. However, when the aircraft weighs under its maximum limit, then the pilot can easily take off the plane using all the above concepts.
Interestingly, modern flight components and advanced onboard computer systems have allowed flying to be easier than ever. Pilots may continue to learn about aerodynamics and its various sub-topics during training, but the fact is that the physics of flight happens in the background instantaneously and automatically without the pilot or passengers even noticing it – and we have scientists and engineers to thank for this!
WHY CHOOSE SHERBURN AERO CLUB
Sherburn Aero Club, which has been operational since 1964, is the ideal place for most of your training and flying needs. It is one of the largest flying clubs in the North of England and also one of the largest in the country.
If you wish to begin your career in aviation or wish to take to the skies as a hobby, Sherburn’s flight training school offers private and commercial licences, along with pilot medicals to ensure a smooth journey going forward.
For those who wish to experience the thrill of a flight for fun or to help fuel their aviation dreams, Sherburn offers experience flights for the newbie, as well as the veteran in various types of light aircraft.
With a large fleet of new aircraft and an airfield refurbishment with new runways, hangars, and an extended clubhouse, we cater to brand-new flyers who have just started their journey to the skies, as well as seasoned flyers who have been operating aircraft for decades.
The flight experience option is also available for people who wish to take to the skies for special occasions, even if they aren’t into aviation in the long run.
Sherburn offers a dedicated day-long Flight Radiotelephony Operator’s Licence (FRTOL) course for those wishing to get the certification, running the first Sunday of every month.
In addition to that, if you are looking for a hangarage for your own aircraft, need servicing or repairs, want to buy a new aircraft or aviation equipment, or are just looking to enjoy and watch the aircraft, Sherburn Aero Club is the place to be.
Call us at 01977 682 674, email us at flightdesk@sherburnaeroclub.com, or message us via our online contact form for more information on light aircraft, training requirements, fee structure, licencing procedures, as well as experience flights and pilot training at Sherburn.
Photo by Sebastian Grochowicz on Unsplash
