| 词条 | Allsopp Helikite |
| 释义 |
The Helikite is a type of kite-balloon or kytoon designed by Sandy Allsopp in the UK in 1993.[1] The Helikite comprises 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. DesignThe Helikite comprises a semi-rigid helium-filled balloon, having a rigid carbon-fibre spine, with the balloon shaped aerodynamically. The balloon is generally oblate-spheroid in shape although this is not essential. Solid spars provide attachment points for payload equipment. In most winds the aerodynamic lift is greater than the aerostatic lift from the helium. The Helikite design is intended for all-weather, high-altitude operation. The round, stubby shape allows it to be flown in any weather or for altitudes up to 7000 ft. In wind, both the main aerodynamic lift and the aerostatic lift are at the front, while the spar weight and keel are at the stern. For operation in extreme conditions, a ballonet may be fitted. ClassificationA Helikite is a new type of tethered aerostat with its own official classification, distinct from any type of balloon. The US Customs classifies a Helikite as "other non-powered aircraft", while the British Civil Aviation Authority's Air Navigation Order has created its own classification as "Helikites" as distinct from "kites" and "balloons". Customs authorities classify the Helikite as a type of kite because of the considerable positive aerodynamic uplift in wind. OperationHelikites 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. Helikites are the only compact aerostat capable of reliably operating at sea.{{According to whom|date=April 2019}} For this reason, small rapid-response surveillance Helikites are part of the emergency oil-spill response system of Scandinavia for operations in the Arctic Ocean. Due to their stability, Helikites are capable of successfully operating non-gyrostabilised cameras.. The British Army military Helikite surveillance system has 34 m³ volume and lifts a lightweight gyro camera with both E/O and IR capabilities. The US surveillance Helikites are 75m³ and carries a larger gyro camera system and targeting equipment. These aerostats outperform a conventional aerostat of twice the size. These Helikites can lift surveillance equipment above the range of small arms fire, effectively making Helikites unassailable to most common threats. The smallest Helikite ever made was of just 0.028m³ (1 cubic ft). It flew well despite its tiny size. The largest Helikite made so far is 250m³ (8,750) cubic ft which has a net helium lift of 117Kg. See also
References1. ^Allsopps UK Patent No.2280381 and US Patent No.6016998A External links
2 : Kites|Balloons (aircraft) |
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