According to Newton’s first law, an object at rest stays at rest and an object in motion stays in motion unless acted upon by an external force. Therefore, airplanes stay in the air because no net force is acting on it. Certainly, there are forces that act on the plane but they all sum to be zero.
however, getting air molecules to push the plane up in order to form the lifting force that should equalize the gravitational force remains the crucial part. To lift the plane, the wings have to be adjusted in a position where it hits more air molecules in the lower side of wing more that on the upper side. That constitutes high pressure on the bottom of the wing and low pressure on the top creating a lifting force that makes the plane fly. Another key part to mention is the thrust engine that creates a horizontal moving force which resists the drag force creating by air resistance. This engine usually consists a jet propeller to achieve
maximum efficiency to help the plane to move forward by pushing air molecules backwards in a very high speed. It also speeds up the air molecules to hit wings which facilitates lifting the plane.
“Once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return.” - Leonardo da Vinci
How Airplanes fly
Written by: MAHMOUD ELSHAZLY