Ever wondered how a airplane, helicopter, or blimp stayed in the air? This page tells you how! It's divided into three sections, airplanes, helicopters, and blimps. So have fun and enjoy this page!

This is the airplane section. It tells how the wings of a flat- bottomed airfoil airplane generate lift, to keep it in the air.
There are many explanations of why the wings on an airplane create lift. But the question still remains, what really makes an airplane fly? The first thing you need to know is that air is a fluid, and fluids have a tendancy to adhere to curved surfaces as they go past. This is the Coanda effect. The wings are shaped so that this effect takes place. But when a fluid goes over a curved surface, its pressure is "thrown" away by centrifugal force. As the air crests the highest part of the airfoil, it wants to pull away from the wing. This creates a slight vacuum in the small space between the air and the airfoil. This helps pull the wing up. That's where the low pressure above the wing high pressure below pulls the wing up theory comes from. But the wing shape has another trick up its sleeve. The shape of the wing causes the air flowing over it to deflect downward, and according to Newton's Third Law, the air going down pushes the wing up, generating a lot of the lift.
But what is lift? Lift is the force that keeps the plane flying. Lift is one of the four forces that keeps a plane flying. But each of the four forces has an enemy. So what's lift's enemy? Weight, or gravity. Without lift, the airplane would fall to the ground like a rock. But if the airplane isn't moving, it doesn't create lift. What is this movement called? Thrust. Thrust is created by the engines. But if the engines would fail, the airplane would slow down. But what is this called? Drag. Drag is the air resistence against the plane.


A blimp's aerodynamics are very simple. Airships are called lighter-than-air (LTA) craft because to generate lift, they use gases that are lighter than air. The most common gas in use today is helium, which has a lifting capacity of 0.064 lb/ft (1.02 kg/m3). Hydrogen was commonly used in the early days of airships because it was even lighter, with a lifting capacity of 0.070 lb/ft3 (1.1 kg/m3) and was easier and cheaper to acquire than helium. However, the Hindenburg disaster ended the use of hydrogen in airships because hydrogen burns so easily. Helium, on the other hand, is not flammable.
While these lifting capacities might not seem like much, airships carry incredibly large volumes of gas -- up to hundreds of thousands of cubic feet (thousands of cubic meters). With this much lifting power, airships can carry heavy loads easily.
A blimp or airship controls its buoyancy in the air much like a submarine does in the water. The ballonets act like ballast tanks holding "heavy" air. When the blimp takes off, the pilot vents air from the ballonets through the air valves. The helium makes the blimp positively buoyant in the surrounding air, so the blimp rises. The pilot throttles the engine and adjusts the elevators to angle the blimp into the wind. The cone shape of the blimp also helps to generate lift. As the blimp rises, outside air pressure decreases and the helium in the envelope expands. The pilots then pump air into the ballonets to maintain pressure against the helium. Adding air makes the blimp heavier, so to maintain a steady cruising altitude, the pilots must balance the air-pressure with the helium-pressure to create neutral buoyancy. To level the blimp in flight, the air pressures between the fore and aft ballonets are adjusted. Blimps can cruise at altitudes of anywhere from 1,000 to 7,000 ft (305 to 2135 m). The engines provide forward and reverse thrust while the rudder is used to steer. To descend, the pilots fill the ballonets with air. This increases the density of the blimp, making it negatively buoyant so that it descends. Again, the elevators are adjusted to control the angle of descent. When not in use, blimps are moored to a mooring mast that is either out in the open or in a hangar. To move the blimp into or out of its hangar, a tractor tows the mooring mast with the blimp attached to it.