MIAMI: US researchers are ramping up their use of unmanned, remote-controlled airplanes this year to penetrate the heart of Atlantic hurricanes in the hope of learning more about what makes the giant storms tick.

But they will be flying the rugged drones from the eastern Caribbean island of Barbados because American aviation authorities won’t let them launch the tiny aircraft from US soil out of concern they could endanger other planes.

Nonetheless, storm researchers are confident their drones, which resemble hobbyists’ model airplanes but can be controlled by satellites, will give them a more complete picture of the core of cyclones than they’ve ever had before.

The drones can fly into the eye of a storm just 91 metres above the sea surface and send back a constant stream of temperature, pressure, wind and humidity readings.

“It can get measurements we couldn’t get otherwise,” said Joe Cione, a research meteorologist with the US National Oceanic and Atmospheric Administration.

“That area of the storm is critical because that’s where the maximum winds are. It will give us a better understanding of where the energy is extracted out of the sea.”

Made by Australia’s Aerosonde Pty Ltd. and worth between $50,000 and $80,000, the unmanned aircraft measure just 2.1 metres long, have a 2.7-metre wingspan, and weigh only 12.7 kg.

They are much smaller and less sophisticated than those used by the US military in war zones. Powered by a tiny 24 cc motor and a single propeller, they can fly at about 113 kph and cover an astonishing 3,220 km on a single 2.5-litre tankful of fuel.

They are catapulted into flight or launched from a moving vehicle, and are initially flown using a joystick before control is transferred to a laptop and then to satellite.

Unlike the manned hurricane aircraft used for years to penetrate cyclones at around 3,048 metres, the Aerosondes will fly a few hundred feet above the ocean, where the critical energy transfer from sea surface to storm occurs.

A continuous data stream promises a huge improvement over the sporadic measurements scientists have taken for years using “dropsondes”, packages of instruments flung from a plane which take “snapshots” as they fall through the storm.

“It’s the difference between taking a photograph and taking a movie,” Cione said. “You’re not going to miss anything.”

The researchers have dabbled with drones before, starting with Tropical Storm Ophelia in 2005.—Reuters