Planes to explore hurricanes
2008-05-27 13:13
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 91m 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 2.1m long, have a 2.7m wingspan, and weigh only 12.7kg.
Huge improvement
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 113km/h
and cover an astonishing 3 220km on a single 2.5l tank full of fuel, Cione said.
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 hunter aircraft used for years
to penetrate cyclones at around 3 048m, 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. An unmanned aircraft spent
17.5 hours aloft in a flight into Hurricane Noel last year.
This year they are hoping for two to five flights.
'We'll be all over it'
But for at least this hurricane season - which starts
on Saturday and runs for six months - the drones will explore far
from US shores. The Federal Aviation Administration has not
given NOAA approval to fly them from US territory.
The agency has issued more than 100 approvals for unmanned
aircraft on projects ranging from searches for illegal aliens
along the US border to wildfire surveillance.
But the FAA said it must be sure the drones could be flown
safely from a US base into an approaching hurricane, a time
when many pilots are moving small planes out of harm's way.
"You have a situation where you have a small aircraft that
has no real ability to see and avoid other aircraft, transiting
an area that might have civilian aircraft in it," FAA spokesperson Les Dorr said.
Hurricane researchers look forward to the eventual approval
of US flights to give them a chance to study hurricanes
nearing the coast for signs of the explosive intensity surges
scientists find most worrisome.
"Once that option's available to us, we'll be all over it,"
Cione said. "That's in the FAA's camp."