The names Helikite and Helikites, are Allsopp's Registered Trade Marks relating to a new type of kite-style aerostat designed and patented by Sandy Allsopp in England.
The name Helikite relates to a combination of a helium balloon and a kite to form a single, aerodynamically sound tethered aircraft, that exploits both wind and helium for its lift. The balloon is generally oblate-spheroid in shape although this is not essential.
Helikites are probably the most popular all-weather, high-altitude, aerostat design in the world. Thousands are operated worldwide, flown over both land and sea.
In all comparative military and civilian trials, Helikites, out-performed all other designs of aerostats for stability in wind, altitude and payload. As a result, Helikites are in use with numerous civilian, research and military organisations worldwide.
Helikites can fly in far higher winds than round balloons, sausage shaped balloons, blimps and most normal kites. Helikites are lighter than air and so also fly without wind. They fly far higher and in far worse weather than normal tethered aerostats and seldom require a ballonet. They are used for aerial photography, lifting antennas, radio-relay, advertising, agricultural bird-control, position marking, and meteorology. The military also use Helikites as jungle marker balloons, for lifting radio-relays, and raising surveillance equipment. A standard military Helikite surveillance system of 34 cu metre volume, will lift twice the payload, to three times the height, in far worse weather than normal blimp-shaped military aerostats of 60 cu metres. Helikites are the only small, practical aerostat system that can lift surveillance equipment above the range of the small arms fire - effectively making Helikites unassailable to most threats.
Size for size, Helikites are by far the most stable tethered aerostat design. This is because the problems of pitch and yaw endemic to other small aerostats are virtually eliminated with Helikites. This pitch and yaw of standard small aerostats is a terrible nuisance for video-surveillance, because the picture is constantly moving and this makes it hard to zoom in. So expensive gyro-stabilised cameras are required for normal small aerostats. Helikites are the only small aerostat capable of successfully lifting non-gyrostabilised cameras as well as gyro-stabilised cameras.
Helikites are lighter than air, however, they also utilise aerodynamic lift in a stable manner when wind is available. Due to their rounder shape, Helikites have a better surface-area-to-volume ratio than blimps so have greater aerostatic lift in no wind. This round shape also eliminates the need for a ballonet in any weather or for altitudes up to 7000ft. Helikites have a spine made of carbon-fibre, so they are a semi-rigid design. In wind, the main aerodynamic lift and also the aerostatic lift on a Helikite is at the front. The spar weight and keel is at the stern, therefore the Helikite of the same size remains stable in far higher winds than comparable blimps. Although they can be made larger if required, the ability of Helikites of any size to cope with high winds also enables them to be very small yet still be very reliable, all-weather platforms. The lack of pitch and yaw movement in high winds makes Helikites very popular with photographers and cameramen.
The solid spars on a Helikite also facilitate the steady attachment of equipment such as cameras, radios, sensors etc.
Helikites have made possible the concept of "personal aerostats" that are small enough for one person to easily operate and yet will fly far higher, and in worse weather, than most huge blimp-shaped aerostats.
Although they are lighter-than-air, Helikites are classified by customs authorities as a type of kite because of their considerable positive aerodynamic uplift in wind. In most winds the aerodynamic uplift is greater than the helium uplift.