Captive helicopter
Encyclopedia
A captive helicopter is a helicopter
which is tethered to the ground with a rope, as with a captive balloon. Captive helicopters can be used for the same purposes as captive balloons.
A primary advantage of captive helicopters is that they can be more accurately steered than captive balloons or kite
s in order to compensate for the influence of the wind. A further advantage is that, unlike kites, they can be launched in the absence of wind. Their main disadvantages are that they require power for their flight and are very noisy.
Unlike kites (which rely solely on the wind for power) and balloons (which require specialty lighter-than-air gases), helicopters are normally powered by aviation fuel
s. However, it is possible to run captive helicopters electrically by running a cable inside the tether line holding the helicopter.
At the end of the 1930s, the German company Telefunken
tried to make a longwave transmission experiment with a captive helicopter driven with a three-phase, AC-power engine. The helicopter should have reached a height of 1000 metres. Because of electrostatic charges induced by earth's electric field
, the fuses melted when the captive helicopter reached a height of 750 metres and the captive helicopter landed roughly.
Helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...
which is tethered to the ground with a rope, as with a captive balloon. Captive helicopters can be used for the same purposes as captive balloons.
A primary advantage of captive helicopters is that they can be more accurately steered than captive balloons or kite
Kite
A kite is a tethered aircraft. The necessary lift that makes the kite wing fly is generated when air flows over and under the kite's wing, producing low pressure above the wing and high pressure below it. This deflection also generates horizontal drag along the direction of the wind...
s in order to compensate for the influence of the wind. A further advantage is that, unlike kites, they can be launched in the absence of wind. Their main disadvantages are that they require power for their flight and are very noisy.
Unlike kites (which rely solely on the wind for power) and balloons (which require specialty lighter-than-air gases), helicopters are normally powered by aviation fuel
Aviation fuel
Aviation fuel is a specialized type of petroleum-based fuel used to power aircraft. It is generally of a higher quality than fuels used in less critical applications, such as heating or road transport, and often contains additives to reduce the risk of icing or explosion due to high temperatures,...
s. However, it is possible to run captive helicopters electrically by running a cable inside the tether line holding the helicopter.
At the end of the 1930s, the German company Telefunken
Telefunken
Telefunken is a German radio and television apparatus company, founded in Berlin in 1903, as a joint venture of Siemens & Halske and the Allgemeine Elektricitäts-Gesellschaft...
tried to make a longwave transmission experiment with a captive helicopter driven with a three-phase, AC-power engine. The helicopter should have reached a height of 1000 metres. Because of electrostatic charges induced by earth's electric field
Electric field
In physics, an electric field surrounds electrically charged particles and time-varying magnetic fields. The electric field depicts the force exerted on other electrically charged objects by the electrically charged particle the field is surrounding...
, the fuses melted when the captive helicopter reached a height of 750 metres and the captive helicopter landed roughly.