Plane-mounted camera detects hazardous volcanic ash in the air
By David Szondy
December 13, 2011
A new invention out of Norway promises to keep the skies of the world open. When a volcano in Iceland erupted in 2010, it spewed out invisible clouds of ash that spread across Europe - effectively shutting down all civilian and military air traffic, stranding millions of people and costing the world economy billions of dollars. Now, a new camera has been developed that will allow pilots to see and avoid volcanic dust clouds, making similar eruptions in the future much less disruptive.
We live in a very complex world that is vulnerable in very surprising ways. A faulty electrical relay can black out the entire eastern seaboard of North America, the "wrong" leaves on the tracks can shut down a national railway network and a stuck valve can turn an oil well into an ecological disaster. On April 13, 2010, Eyjafjallajökull was a volcano in Iceland that most people had only heard of in the more fiendish crossword puzzles. It spat out the odd bit of lava on occasion, but for the most part, it behaved itself. Then, on April 14 it blasted a massive jet of ash high into the atmosphere that was caught by the winds and spread all over Europe. Over 330 million cubic yards (250 million m3) of ash was hurled up, but by the time it settled over the British Isles and the Continent it was so diffuse that it only made its presence known in spectacular sunsets.
For airplanes, on the other hand, the ash was a nightmare. It would get sucked into jet engines where the superheated gases would make the silica particles act like a sandblaster on the engine's delicate parts - stopping or even destroying them in midair. Faced with the possibility of airliners dropping from the skies, the European air authorities had to make a decision. So, based on computer models supplied by the British Met Office showing the extent of the ash coverage, they decided to shut down all air traffic rather than risk a major disaster.
Ash shuts down European airspace
The result was the worst air transport disruption since the 9/11 attacks. Airlines lost US$1.7 billion in revenues and the general economy lost billions more. Millions of passengers were left stranded as ferries, railways, coaches and hire cars failed to take up the slack. Newspapers were filled with stories of people hiring small boats to cross the English Channel and comedian John Cleese spent $3,300 on cab fare from Norway to Brussels.
The worst of this was that this precaution was borne largely out of ignorance. The Icelandic volcano did erupt, the ash was certainly a threat and the computer models did identify the extent of the threat, but it turned out that the Met Office and other agencies didn't have any operational sample planes to actually go up and measure the ash in the air. This was critical because the ash didn't spread evenly over Europe. Instead, it came in plumes and clumps. Airlines argued that they should be able to fly because the ash wasn't dangerous everywhere. One even sent up a "verification flight" to prove it, but the authorities erred on the side of caution.
All of this is more than a history lesson because Eyjafjallajökull is still active and, worse, it has a neighbor volcano that is larger and just as likely to erupt. A second ash cloud spewing away in the current economy doesn't bear thinking about. If only there was some way to see the ash plumes, then there might be a way to reduce the impact.
Enter Australian Fred Prata of the Norwegian Institute for Air Research (NILU). Under funding from Easyjet airlines, Prata has developed AVOID (Airborne Volcanic Object Imaging Detector). Based on technology originally designed for Earth-orbiting satellites and built by Nicarnica Aviation, his wing-mounted infrared camera closes the gap between the volcano and the computer model without having to build expensive fleets of sample planes. Since it works in the infrared range of the light spectrum. AVOID can see the ash particles in day or night up to 60 miles (100 km) away and when combining what it sees with air speed and GPS data, it can display ash concentrations in real time. Since the ash is in plumes and clumps, AVOID can tell planes where to fly safely even in conditions produced by the 2010 eruption.
But the really clever thing about AVOID is that it isn't intended to be used in special meteorological aircraft. It's meant to be mounted on ordinary airplane wings, so airliners can look out for themselves. In this way, a continental disaster can be reduced to a local problem.
After previous experiments with volcanoes in Japan and the Mariana Islands as well as during the 2010 eruption, AVOID has undergone extensive testing recently, including 10 days guiding a light aircraft through the ash plumes from Italy's Mount Etna. Easyjet was so impressed with the result of their investment that they are installing AVOID on 20 of their Airbus aircraft in 2012 and will make the technology available to other airlines. It may not keep volcanoes from exploding, but it does make the aftermath a little easier to deal with.
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