Airplanes are like the human technological equivalent of shooting stars in the night sky, except they are more frequent, and can carry people to countries and continents miles and oceans away!
A true milestone in the emergence of faster and safer modes of transport, airplanes made their first successful historic debut as the futuristic creation by the Wright brothers in 1903. Ever wonder how these heavier than air machines actually manage to stay in the air and fly, taking the load of numerous people and their luggage no less? Let’s take a look!
Four major factors play a role in ensuring that a flight flies, those are-
- Lift — The movement of the air around the wings of a plane generates lift which pushes the aircraft up. The lift is also helped by the streamlined shape of the flight and it’s wings and by the air pressure surrounding it.
- Weight — This is the force that pushes the aircraft towards earth. Airplanes are designed to withstand this pull having its weight distributed from front to back allowing for a balanced flight. Weight is opposite to Lift.
- Thrust — This force pushes the airplane forward propelled by the jet engines which lets the air go over its wings. Thrust is opposite to Drag.
- Drag — The force that works against the aircraft, slowing it down, caused by friction and air pressure. It’s similar to trying to walk during heavy winds. The design of aircrafts are streamlined in order to reduce the drag by allowing the air to pass smoothly.
So these four forces work in tandem and oppose their counterparts to allow the flight in an airplane. The engine produces enough thrust to overpower the force of drag letting the aircraft move forward initially. Once enough thrust has been achieved by the aircraft it starts generating the force that allows for the aircraft to be lifted up overcoming the pull of earth’s gravity produced due to the aircraft’s weight.
The air that moves around the aircraft is aided by the shape of the wings, which is slightly curved. This means that the stream of air is split in half, and the air below the aircraft and its wings have a higher atmospheric pressure while the air above it has a lower air pressure. This generates an upward force allowing the aircraft to attain elevation.
Can They Stay Still in the Air?
Another question that may pop into the heads of bright, curious minds is whether aircrafts, more importantly, flights are capable of staying stagnant in the air without movement and or hover. This phenomenon can only, only occur if all the four forces, i.e., Lift, Weight, Thrust and Drag, cancel each other out simultaneously. And in the case of airplanes, as mentioned earlier, they can only achieve lift by moving forward, which is created by thrust. Therefore, without motion they’re incapable of lift and cannot hover above ground without forward movement.
This phenomenon is more theoretical than it is practical and extremely rare to be seen in reality since the cancellation of the forces are largely dependent on external factors like wind velocity, atmospheric hindrance, gravity, etc. and thereby making it nearly impossible.
What About Helicopters?
The next question posed then would be, helicopters are aircrafts too and they can hover, so how do they do it? Now, in the case of a plane, it has its wings on both the sides flanked by the engines and propellers which create the forces mentioned above, allowing the aircraft to take flight. But, what about helicopters? They can fly and hover too, can’t they? This is because they have an entirely different type of design with rotors on top of them and unlike aircrafts, they don’t need to be propelled forward to achieve lift, rather they just seem to be lifted up. So, how does this work? Lets see how!
Well, helicopters are what one calls a rotary wing aircraft. Meaning they have big fan-like wings (rotor blades) with a rotor attached to the engine on top of its body, and are rapidly turned by the engine, mimicking the motion of a fan, literally! However, these blades move at such a speed, it generates enough force or lift to pull the helicopter up off the ground overcoming the weight of it and the gravitational pull caused by it to the earth.
This means that when the rotary wings move at a high speed, the force it generates pushes downward on the aircraft, splitting the air stream under and above each wing. The air pressure above the wings is lower than the pressure below the wings, similar to the working of the wings on an airplane, creating lift. Helicopters can hover because of their rotary wings, allowing for vertical take-off without forward motion. The aircraft’s movement is then controlled by the pilot by tilting the rotors in a back and forth or side to side motion.
But these types of aircrafts, helicopters that is, typically have a smaller rotary propeller towards the end, so what’s its purpose? Well they function to ensure that the whole aircraft doesn’t turn when the rotor blades atop move to create lift and fly. This is how aircrafts like helicopters and airplanes navigate the skies and take us to places within the shortest period of time, whilst allowing us to enjoy the skies, the sunsets and the sunrises amongst the clouds!