A free online aircraft recognition guide for everyone!

Theory of Flight - Aircraft Forces


Let's start by explaining the 4 Forces on an aircraft. These are lift, thrust, drag and weight as shown in the image below.


Aircraft forces
Q: How does a wing generate lift?


Q: How does an engine provide thrust?


Q: What are the different parts to an aircraft called?


Drag is the force opposite to thrust. It creates resistance to the forward movement of the aircraft and must be kept to a minimum. Aircraft companies constantly compete to reduce drag. This would enable the aircraft to travel faster and further on the same amount of thrust.



Thrust is the forward movement of the aircraft, provided by the aircrafts engines. The thrust of the aircraft must always be greater than the drag in order to sustain lift. How do engines provide thrust?



Lift of an aircraft happens when the aircraft reaches a sertain speed. This would mean that sufficient amounts of air is passing over the wings to generate the lift. How does a wing generate lift?



Obviously the weight of the aircraft is the pulling down force on the aircraft obviously cause by gravity. If there was none, we wouldn't need to worry about lift or weight. The weight of the aircraft acts vertically downwards through its centre of gravity.


For many of us, the 4 forces that act on an aircraft are listed below!

4 Forces funny