Wednesday, July 2, 2014

Triumph of Weather Science: Conquering the Downburst

Twenty years ago today was the end of an era.

The crash of USAir Flight 1016 at Charlotte-Douglas International Airport, twenty years ago today, killed 37. The crew flew, while discussing the potential for wind shear, into a microburst. The plane rapidly lost altitude, plowed through a stand of trees, and crashed just west of the airport.
The crash of USAir 1016
It was the last of a series of horrific airliner crashes caused by downbursts -- areas of intense wind shear (rapid change in wind speed and/or direction in a short distance) -- every 12 months on average since 1973. A period when just about every adult American knew what "wind shear crash" meant. Consider this staggering (by today's standards) list of accidents and incidents:

  • Ozark Airways, St. Louis, 1973
  • Eastern Air Lines, New York, 1975
  • Continental Airlines, Denver, 1975
  • Allegheny Airlines, Philadelphia, 1976
  • Continental Airlines, Tucson, 1977
  • USAir, Dayton, 1982
  • Pan American Airways, New Orleans, 1982
  • Air Force One, Andrews Air Force Base, 1983
  • USAir, Detroit, 1984
  • United Airlines, Denver, 1984
  • Delta Air Lines, Dallas-Ft. Worth, 1985
After the investigation of the crash of Eastern Flight 66 in 1975, Dr. Ted Fujita and Dr. Horace Byers published a paper (1977) hypothesizing the existence of a previously undiscovered type of storm they named a "downburst" and that a downburst caused the crash. This differed from the official cause of the accident. 

The paper ignited a firestorm in weather science (similar to the global warming controversy): Most meteorologists and aviation specialists believed Fujita and Byers had misunderstood the evidence. 

In 1978, I provided Dr. Fujita with additional evidence in the form of a series of photographs documenting the life-cycle of a downburst (one appears above). Fujita also collected radar evidence of downbursts through a meteorological project (known as NIMROD) in northern Illinois. He continued to periodically publish this evidence supporting his hypothesis but skepticism was so high that one headline in 1979 asked if downbursts were just "hot air." 

Dr. Fujita was called in to investigate the crash of Delta Flight 191 at DFW International Airport on August 2, 1985, killing 137. The L-1011 jumbo jet had a new digital black box that yielded much more data than the black boxes on the planes involved in the earlier crashes. Combined with instrumentation from the airport, Fujita was able to conclusively demonstrate a downburst caused the crash. 

The meteorological and aviation (metaphorical) winds shifted immediately. The FAA developed training materials for airline pilots, wind shear detection systems were deployed and upgraded, and 44 high risk airports received a new radar called Terminal Doppler Weather Radar. Instead of every 12 months on average, the next downburst crash took almost nine years to occur, the event we commemorate today.

Since that time, there hasn't been a single downburst crash. And, thanks to weather science, it was the beginning of an era of much safer air travel where adults in their twenties have never even heard of wind shear. Think about it: Can you even remember the last crash of a U.S. mainline airliner?* 

Dr. Fujita (who passed away in 1998) deserves our thanks for his courage, talent and tenacity in the face of tremendous criticism that caused him "many sleepless nights."
Dr. Fujita (center) visiting WeatherData, Incorporated in 1992 
The full story of how meteorologists unravelled the mystery of the downburst, including the fascinating civil trial in the wake of the crash of Delta 191, is told in my book, Warnings: The True Story of How Science Tamed the Weather. Whether it is saving lives in tornadoes (recall last month's triple tornadoes in Nebraska), creating more specific and useful hurricane warnings, and making air travel safer, weather science doesn't get credit for its amazing successes. So, pick up a copy of the book. You'll find it is great reading.

And, the next time you safely land with thunderstorms in the area -- thank a meteorologist. 

*The last fatal crash of a major U.S. airline's jetliner was December 8, 2005. It was Southwest Flight 1248; no one on the plane was injured. A runway overrun in snow killed one person on the ground at Chicago's Midway Airport. We are approaching nine years without a passenger fatality in a mainline jet of Southwest, United, American Airlines, USAir (or their predecessor airlines), JetBlue, Spirit or Allegiant. That is a remarkable achievement.  

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