Thunderstorm Alert System Could Thwart Plane Crashes

Andrea Thompson

Date: 07 July 2009 Time: 09:08 AM ET

This photograph, acquired in February 1984 by an astronaut aboard the space shuttle, shows a series of mature thunderstorms in southern Brazil.
CREDIT: NASA

A new guidance system in the works could help transoceanic flights avoid dangerous thunderstorms, such as the ones thought to have played a part in the recent fatal crashes of two jetliners.

Air France Flight 447 apparently encountered severe thunderstorms over the Atlantic Ocean just before it crashed en route to Paris on June 1. And Yemenia Flight 626 also encountered strong winds and turbulence before it crashed June 30, just short of the island of Comoros.

Thunderstorms can pose a threat to aircraft, particularly in the stormy summer months, mainly because of the convective motion of the air within storms. The powerful updrafts and downdrafts can push a plane around, potentially damaging it or worse.

(Despite bad weather and other risks, flying remains the safer than driving.)

Dedicated forecasters and air traffic controllers typically send weather updates to pilots to help them avoid hazardous weather, but this can be hard over areas of remote ocean where planes are no longer on air traffic radars or in communication range with air traffic towers. Weather conditions can change quickly, making preflight briefings obsolete. Onboard radars provide information on clouds and precipitation, but the worst turbulence can be far away from the worst rain.

A new prototype system being developed by scientists at the National Center for Atmospheric Research in Boulder, Colo., aims to address these problems with improved in-flight, real-time weather maps that could be sent to pilots via satellite uplink.

"Pilots currently have little weather information as they fly over remote stretches of the ocean, which is where some of the worst turbulence encounters occur," said John Williams, one of the project leaders. "Providing pilots with at least an approximate picture of developing storms could help guide them safely around areas of potentially severe turbulence."

The NCAR system, being developed with funding from NASA, combines satellite data and computer weather models with cutting-edge artificial intelligence techniques to identify and predict rapidly evolving storms and other potential areas of turbulence.

The system is on track for testing next year. Pilots on selected transoceanic routes will receive real-time turbulence updates and then provide feedback on the system to the scientists. The system should be finalized in about two years.

The component of the system that identifies major storms over the ocean is already available for aircraft use on an experimental basis.

If such a system as the one NCAR scientists are developing had existed last month, it might have alerted the pilots of the doomed Air France flight, for instance, to the stormy conditions along their flight path. The cause of that disaster has not been determined though, and it is impossible to know for sure whether the system could have prevented it.

"It seems likely that the information provided by a real-time uplink of weather conditions ahead would have, at a minimum, improved the pilots' situational awareness," Williams says.