Allsopp Helikite

Did You Know?

• The US Customs classifies a Helikite as 'other non-powered aircraft'.
• The British Civil Aviation Authority's Air Navigation Order has created its own classification of 'Helikites' distinct from 'kites' and 'balloons'.
• Customs authorities classify the Helikite as a type of kite because of its considerable positive aerodynamic uplift in wind.

Design

The Helikite, developed by Allsopp Helikites Ltd., is a hybrid balloon with a semi-rigid, aerodynamic shape. It has a helium-filled envelope and a rigid carbon-fiber spine, with solid spars for attaching payloads. Its form is roughly an oblate spheroid. In most conditions, the lift from the wind is greater than the lift from the helium. This design works in all weather and can reach up to 7,000 feet. When the wind blows, the main lifting forces are at the front, while the spar and keel sit at the back. Compared to traditional aerostats, Helikites are much smaller because they use wind lift instead of relying mostly on helium to fight high winds. This smaller size means they fly much higher for their size, have fewer seams so less gas leaks, and use far less helium. They also lack ballonets and don't need constant power to stay up, making them simpler. Their stability makes them good platforms for cameras or scientific gear. Tiny versions work in any weather, are easy to handle, and don't need big winches. A small Helikite can fit fully inflated in a car, while larger ones carry heavy payloads higher. Sizes range from 1 meter (lifting 30 grams) to 14 meters (lifting 117 kilograms). Small models fly up to 1,000 feet, medium up to 3,000 feet, and large up to 7,000 feet.

Operation

Helikites are used for aerial photography, lifting antennas, radio-relay, advertising, agricultural bird-control, position marking, and meteorology. Military applications include jungle marker balloons, lifting radio-relays, and raising surveillance equipment. After sea-trials, Norwegian and British oil-spill response organizations determined Helikites were the only compact aerostat reliably operable at sea, leading to their inclusion in emergency oil-spill response systems in Scandinavia and the UK for Arctic Ocean operations. Helikites can operate non-gyrostabilised cameras due to their stability. The British Army uses a 34 m³ Helikite with a lightweight gyro camera; US surveillance Helikites are 75 m³ with larger gyro camera and targeting equipment. These outperform conventional aerostats twice their size and can lift surveillance equipment above small arms fire range. The smallest Helikite ever made was 0.028 m³; the largest, 250 m³, was used by the Max Planck Institute for cloud droplet research at 7,000 feet from ocean research ships.