‘Watch Where You Fly!’

In 1989, a new 727 jumbo-jet was flying at 25,000 feet, when it flew right into an ash cloud from a volcano. The pilot thought the ash cloud was a regular rain cloud. Suddenly, she noticed brown ash in the cockpit. Then, all four engines conked out, and the plane lost power. Volcanic ash, made up of tiny shards of glass, melted in the engines, then cooled into solid clumps of glass, clogging the engines’ air vents, and causing all four engines to stall. The plane dropped 12,000 feet with no power. Then, luckily, the pilot was able to restart the engines and land safely. But, all four big jet engines were damaged beyond repair.

FOR THE RECORD:
Kids’ Reading Room: In the story “Watch Where You Fly!” on the Jan. 2 Kids’ Reading Room pages, the jumbo jet is referred to as a 727 that has four engines. It should have referred to a 747. The 727 has only three engines.

Volcanic ash is not like our wild fire ash. Wild fire ash is like the ash left over from a fire in a fireplace. But volcanic ash is a lot different. Volcanic ash is made up of tiny, floating particles of broken glass. It’s quite unhealthy for humans and animals to breathe.

Where does volcanic ash come from? It comes from erupting volcanoes. What exactly is a volcano? A volcano is an opening in a planet’s surface. From far below the Earth, molten rock, ash and gases escape through this opening. This is called an eruption. In the U.S., the most recent big volcano eruption was in 1980, when Mt. St. Helens in Washington blew its top. There are other active volcanoes in the U.S. in Hawaii and Alaska.

But none of the U.S. volcanoes is like Mt. Merapi in Java, Indonesia.

Mt. Merapi erupts often. This year was Mt. Merapi’s biggest eruption since 1870. It forced over 350,000 people to leave their homes in a blizzard of powdery ash. The ash was so fine the people looked as if they had fallen into vats of flour. Everything was buried under several inches of gray, ashy snow. Mt. Merapi could be called a “hyperactive” volcano. It erupts every few years, making big trouble for the people who live close by.

And of course, big trouble for airplanes. Even far from the volcano the ash plume is dangerous to airplanes. Part of the reason is that it thins out and becomes invisible to pilots. When a plane flying 400 miles per hour hits those little splinters of grit, the windshield gets sandblasted. The pilot may not even be able to see through all the little chips and scratches in the glass. The ash can also damage the skin and other outside parts of the airplane.

So, how do pilots know where it’s safe to fly?

Satellites!

What is a satellite? A satellite is equipment that orbits the Earth or the moon. With this equipment we can see the Earth’s atmosphere up close.

From space, even a thin cloud of ash looks slightly different from clear air and rain clouds. With help from a computer, satellite images–even those taken at night–can highlight volcanic ash. This information is reported to air traffic controllers, who warn pilots to stay out of the broken glass!

A new kind of satellite, called GOES-R, will help even more with aviation. GOES-R stands for Geostationary Operational Environment Satellite, “R” series. NASA plans to launch the first one in 2015. The National Oceanic and atmospheric Administration (NOAA) will operate it. GOES-R will be able to help flight controllers plan safe flight paths. It will provide quick and accurate data about not only volcanic ash plumes, but also dangerous turbulence and lightning.

Play the new “Flight Controller” game at https://scijinks.gov/aviation-game, and use GOES-R’s hazard maps to plan safe flight paths for your airplanes.

This article was provided through the courtesy of the Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, under a contract with the National Aeronautics and Space Administration and support from the U.S. Department of Commerce National Oceanic and Atmospheric Administration.