Have you ever come to wonder what makes an aeroplane fly, how it goes up and defies the laws of gravity. In order to find out why we must find out the forces acting on an aeroplane :-
- LIFT – force generated by the aerofoil that tends to push an aeroplane up.
- GRAVITY – force generated by nature that tend to pull an aeroplane down
- THRUST – force generated by the jet engine that tends to push an aeroplane forward
- DRAG – force generated by wind that tends to pull an aeroplane backwards.
- In order for an plane to move forward the thrust must be greater than the drag
- In order for the plane to move up the lift must be greater than the gravity.
To understand why the plane flies we need to look at the aerofoil:-
A plane goes up despite its weight and gravity because of a specially created wing shaped as an aerofoil. Air on the top of the wing travels further and faster while air at the bottom travels a shorter distance than above hence a high pressure is created at the bottom and a lower pressure is created at the top. This brings about the lift.
This was a great discovery by the wright brothers who were the first people to make the first successful flight. The ingenuity of there aerofoil idea has gone on to the current flight. many advancement have been made but the wing remains the same.
The engine will be discussed in a later topic but it can be either a piston engine or gas turbine. Its job is to create thrust to move the plane forward. In piston engine there is either petrol or diesel 4 stroke engines. This will be explained further in our mechanical engineering page. The gas turbine engine may either be turbo shaft as in helicopters, turbo prop, turbo jet and turbo fan.