What balances an airplane in the air?

Travelling by air is currently the fastest form of transportation. Of course, like other forms of transportation, there have been improvements in speed, luxury, and safety of airplanes over the years. One question you may have forgotten to ponder though is how does an airplane attain balance in the air like a bird with two wings?

There are four forces that are integral to the operation of an airplane. These forces are weight, thrust, lift and drag. Weight is the force that tries to pull down the mass of people and cargo on a plane due to gravity. Weight is the addition of all masses on a plane including men and goods and then multiplying with acceleration due to gravity.

Boeing 787

Thrust is the force from the propeller engine of an airplane that propels a plane forward. Lift is the force that pulls a plane up through reduced pressure on the upper part of its wings. Drag is the resistance that opposes the movement of a plane in the air.

These four forces all vary depending on the action being carried out by an airplane. When a plane is trying to take off, the thrust is more than drag which is the opposing force to thrust while the lift is more than weight, its opposing force. Of course, it is vice versa when it is landing.

The two major forces responsible for the balance of an airplane while it is on cruise are the lift and weight.

Lift must balance out the weight for the plane to remain in the cruising state. There are not much technicalities about weight but the same cannot be said of lift. Lift is possible because of many theories.

Newton’s laws of motion and Bernoulli’s principle are the major theories that explain lift of an airplane. Bernoulli’s principle simply explains that pressure of a fluid reduces when an object is moving through it at an increasing speed.

During takeoff, the pressure at top of the wings reduces at increasing speed. This makes air particles at the top of the wing move faster than that below the wings. The pressure above the wings is also lower than below the wings.

This phenomenon results into lift of the plane into the air. There are other factors like angle of attack and other complex revelations but I guess I’ll save you from that today. One other factor important to the lift is the amount of air diverted down horizontally from the lower part of the wing.

Big airplanes divert more air downwards to balance the weight of the plane. When the speed of a plane increases, its angle of attack reduces to maintain the same lift against its weight.

The lift force also explains why the wings of airplanes increase in length with size. That is why the wings of a plane like Airbus A380 or Boeing 747 or a large cargo plane will be longer than smaller planes. This is to increase the lift which will balance the enormous weight of these planes.

Technology and engineering has gone forward to a tremendous height over the years but it is still an engineering marvel that man can be able to stay in a machine for 10 hours in the air and still feel completely safe.

Posted in Machines, Specials, technology