Four Forces of Flight

When it comes to airplane travel, that is pretty much our experience. We are more concerned about comfort, available amenities, and food. We see them every day: airplanes, jets, and helicopters, soaring, zooming, and even roaring through the skies, but how many you actually have sat back and indulged yourself in the physical amazement of how a 975,000 lb. ballerina, like a 747 jumbo jet, leaps up into the atmosphere, and when its time, settles so graciously back to the bondages of terra firma? As a Commercial Pilot with over 800 hours, I am in constant awe of the fidelity of the principles and laws that allow me to escape the grips of gravity and observe the aerodynamics of flight.
Although, there are many concepts when it comes to aerodynamics, I’m going to discuss the four major ones today. Lift, weight, thrust, and drag. During flight, there is a constant relationship between these forces. Lift is the upward force created by the effect of airflow as it passes over and under the wing. The airplane is supported in flight by lift. Weight, which opposes lift, is caused by the downward pull of gravity. Thrust is the forward force which propels the airplane through the air, which varies with the amount of engine power being used. Opposing thrust is drag, which is a backward, or retarding, force which limits the speed of the airplane. I’m also going to introduce Newton’s second law, which explains how an object will change velocity if it is pushed or pulled upon, Newton’s third law, which states that forces always come in equal and opposite pairs, as well as Bernoulli’s principle, which explains how the differences in pressure create lift.
Lift is the key aerodynamic force. It is the force that opposes weight. A plane that sits on a runway doesn't have any lift, but it does have weight. Bernoulli's principle also applies to lift in the following manner: Air passes over the top of a wing, which results in lower pressure, while high pressure is generated under the