How do blimps work?

Question

Not what keeps them in the air, but what controls them? Are they tethered to the ground, remotely controlled, or is a pilot actually in control?

Answer 1

blimps have a control room where a pilot can control the direction of flight with rudder, elevators, and on some blimps they even have ailerons.

(the control room is usually under and toward the front of the blimp)

in addition the direction of movement is controlled usually by engines driving propellers. certain blimps have movable engines so that the usually control surfaces are not needed. the pilot just adjusts the engines to point in the direction he wishes to go.

some blimps, such as the ones used in WWI as anti-aircraft blimps to prevent enemy aircraft from bombing key positions are tethered and pilotless.

Answer 2

There's a pilot

Answer 3

for pics etc click on the link

How a Blimp Flies

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/ft3 (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.

Uses of Blimps and Airships

Photo courtesy Goodyear

Blimp covering a Cleveland Browns football game



Because gas provides the lift in an airship or blimp, rather than a wing with an engine as in an airplane, airships can fly and hover without expending fuel or energy. Furthermore, airships can stay aloft anywhere from hours to days -- much longer than airplanes or helicopters. These properties make blimps ideal for such uses as covering sporting events, advertising and some research, like scouting for whales.

Recently, there has been renewed interest in using rigid airships for lifting and/or transporting heavy cargo loads, like ships, tanks and oil rigs, for military and civilian purposes. Modern airships, such as the Zeppelin NT and CargoLifter, use lightweight, carbon-composite frames that allow them to be huge, light and structurally sound. In addition to hauling cargo, airships may once again be used for tourism. So, the sight of a large airship moving across the sky may become more common in the near future.

Answer 4

they have propellers that direct them...

Answer 5

Well to be honest everything is possible. Usually something that floats through the air but is tethered is called an Aerostat. It can be used for advertising at events, pretty much like a big party balloon or for surveillance. The US Navy for example as huge Aerostats that carry radar antennas. Aerostats since they are tethered usually have no means of propelling them self through the air. A remote controlled blimp is usually relatively small, it can carry maybe 10 kg but not enough weight so that a human could sit in it. Those RC-Blimps or RC-Airships are usually used for camera platforms or for other surveillance work but also at events to fly above a crowd for advertising. A pilot being in control requires the Blimp to have a certain size the smallest ones are carrying at least to people. Those Blimps are usually quite big the Goodyear blimp has to be handled on the ground by 12 grown up men. The Pilot usually sits in the Gondola underneath. Typical for Blimps is that the propellers are attached to that gondola and that the envelope is pretty much a gas bag with no rigid structure in is, so if you let the helium out it will lie flat on the ground. Other types of airships are semi-rigid and rigid defining how their shape is, a semi rigid airship like the Zeppelin NT has some kind of skeleton inside that allows it to keep most of it's shape and that allows the propeller to move away from the gondola so that it is more quiet. A fully rigid airship like the Hindenbug or the Graf Zeppelin, has a hull that is more or less solid. For example the Hindenburg had it's passenger rooms inside the hull and not underneath it, you could even walk around inside, something that's not possible in a Blimp. If you have more questions go a head and ask, myself and a whole team of Airship specialist enjoy answering your questions.

Regards,

Andreas G

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Editor of Airshipworld

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