How do Airplanes fly?

Answer 1

It all has to do with pressure, momentum and energy of the air as described by Bernoulli's Equation which is a simplified form of the Momentum Equation.

The key idea: As air moves faster, the local pressure drops.

The wing is designed such that the air moves faster on the top of the wing than on the bottom.

The result is the top of the wing is at a lower pressure (faster moving air), while the bottom is at a higher pressure (slower moving air). Due to the pressure difference, a net force pushes the wings up.

When the wing is large enough, you'll have more up force (Lift) than down force (gravity). The result is flying.

You feel lift when you stick you palm out (at an angle) of a moving car's window.

Answer 2

There are four factors which act on an aeroplane in flight. Weight, Thrust, Lift and Drag.
Before an aeroplane can fly the thrust provided by the engines must overcome the drag produced by the aircraft's shape and the lift generated by the wings and other flying surfaces must overcome the weight of the aircraft and passengers/cargo.
Lift is achieved by the shape and angle to the airflow of the wings. As the aircraft is accelerated through the air the wings produce lift which overcomes the weight and the aeroplane becomes airborne. The thrust of the engines maintains flight and overcomes any drag. A better question (and a whole lot more frightening) is given the above facts how doers an aeroplane come back to land. I believe it's called a controlled crash.

Answer 3

It's all down to the shape of the wings.
The shape creates a change in air pressure above the wing and creates a lifting force when the engines push the aircraft along.

An aircraft needs something to counteract its weight and get it into the air. This is called 'lift', and is generated by the wings.

Wings have a special shape - usually curved on the top and flat on the bottom. As air flows over the wings, the air on the top is forced to take a slightly longer path than the air on the bottom, so it has to speed up.

This causes the pressure on the top to be lower than that on the bottom, which effectively 'sucks' the wing upwards.

Answer 4

Here's my reply to a similar question asked a few days ago:

Just before the plane takes off, you probably have noticed that it races down the runway at higher and higher speed before it finally lifts off into the air. That's so that, as the air flows across the plane's wings , it creates a force called the "lift" that actually pulls the plane upwards.

As long as the plane moves forward at a certain speed in the air, that "lift" force would keep on maintaining it airborne. For a helicopter, the rotor as it rotates create the lift since each blade is shaped in the same form as a wing on a regular airplane. That's why, a helicopter does not need to move forward to stay in the air as long as its rotor keeps on rotating!

Answer 5

The wings are designed to make the air above it travel farther. The top of the wing is curved, and the bottom flat. Since the air on top and bottom have to get to the end point(the back of the wing) at the same time, the air on top of the wing travels faster. The faster air has a lower pressure than the slower air. Thus creating "lift" upwards. The trick is to get the air above the wing fast enough to lift the plane off the ground.

Answer 6

They use powerful engines to increase speed (so powerful they can flip your car!!!). Also aerodynamics play a big role (its easier to move a round object than a box). When desired speed is obtained, part of the wings move down making the air push the airplane up. When landing, it's the other way around, the wings tilt up making the plane go down!!!

Answer 7

The pilot push the throttle into maximum. Put flaps into 15. Co-pilot check the radio. Flight engineer check engine state.
The plane start moving forward. At 120 knots, the pilot pull the joystick, 15 degree angle of attack...and the plane start flying. 800 feet altitude reached and positive speed, pull up the landing gear and pull up the flaps. Ascending until 30000 feet. put the auto pilot, set the waypoint, there you are...Plane is flying and you can go to lavatory.

Answer 8

Is a simple bit of physics, the take off is the hard part.

Planes take off due to the wind speed over the wing, and is goverened by Bernoulli's principle - states that in an ideal fluid (low speed air is a good approximation), with no work being performed on the fluid, an increase in velocity occurs simultaneously with decrease in pressure or gravitational energy.

This principle is a simplification of Bernoulli's equation, which states that the sum of all forms of energy in a fluid flowing along an enclosed path (a streamline) is the same at any two points in that path. It is named after the Dutch/Swiss mathematician/scientist Daniel Bernoulli

So in English, a simple explanation would be that the wing is larger on the upper surfce, than it is on the lower one. thus when the air flow hits it, it is divided. This causes a pressure differential above and below a wing. the one under the wing is greater, and pushes the wing up.

However, this explanation often uses 'false' information, such as the incorrect assumption that the two parcels of air which separate at the leading edge of a wing must meet again at the trailing edge, and the assumption that it is the difference in air speed that causes the changes in pressure.

In air (or comparably in any fluid), lift is created as flow interacts with an airfoil or other body and is deflected downward. The plane on the runway, has a wing that is angled downward. The propeller, or jet moves the plane forward, thus the force created by this deflection of the air creates an equal and opposite upward force according to Newton's third law of motion. The deflection of airflow downward during the creation of lift is known as downwash.

It is important to note that the acceleration of the air does not just involve the air molecules "bouncing off" the lower surface of the wing. Rather, air molecules closely follow both the top and bottom surfaces, and so the airflow is deflected downward. The acceleration of the air during the creation of lift has also been described as a "turning" of the airflow.

this is enough to lift the weight of the plane, and allow it to accelerate to 50-70 mph. the wing thus takes on its flying profile, but on large passenger jets, additional truning is created by Flaps, which extend out of the wing, and cause huge downwash.

The Helmholtz theorem states that circulation is conserved; put simply this is conservation of the air's angular momentum. When an aircraft is at rest, there is no circulation. As the flow speed increases (that is, the aircraft accelerates in the air-body-fixed frame), a vortex, called the starting vortex, forms at the trailing edge of the airfoil, due to viscous effects in the boundary layer. Eventually the vortex detaches from the airfoil and gets swept away from it rearward. The circulation in the starting vortex is equal in magnitude and opposite in direction to the circulation around the airfoil. Theoretically, the starting vortex remains connected to the vortex bound in the airfoil, through the wing-tip vortices, forming a closed circuit. In reality, the starting vortex is dissipated by a number of effects, as are the wing-tip vortices far behind the aircraft. However, the net circulation in "the world" is still zero as the circulation from the vortices is transferred to the surroundings as they dissipate.

The aircraft starts to fly at the point that this vortex breaks from the wing. The large jet then lifts the flaps back into the wing, thus reducing the lift of the wing, but also reducing the drag, so the plane can speed up, to compensate the loss of wing area.

The circulation of a big wing is so much during take-off, that light aircraft can not take off after a large jet has done so. In flight, the plane remains stable if the center of gravity is in front of the middle of the wing. The weight of the engine of petrol planes means that the control wings are positioned at the back to maintain a working balance, however, placing the wing at the back is a far more stable configuration. The propellar would be pushing, which is not so good, so many aircraft keep the normal configuration.

Answer 9

They fly by having an aerodynamic design as well as overcoming the forces of flight. You have four forces of flight:

Thrust, Lift,Weight, and Drag: Thrust refers to the force used to move the plane, weight refers to the weight of the aircraft, drag refers to the force exerted by the parts that extend from the plane such as the wings, ailerons, lift refers to the force required to "lift the plane into the air.

Thrust must overcome Weight so, a 40,000 lb airplane will require more than 40,000 lbs of thrust to lift it. Secondly, lift must overcome drag. lift must overcome drag by making the parts that extend from the plane (such as wings) as smooth as possible so that air can pass over them smoothly by creating a flat a surface as possible thus lifting the plane into the air. If you need more info just e-mail me.

Answer 10

Essentially, when an airplane acclerates, the pressure pushing up underneath the wings becomes greater than the power of gravity and the whole thing lifts up into the air.