Monday, August 2, 2010

The 25th Anniversary of the Crash of Delta 191

At 9:30am this morning, a long-overdue memorial to the victims of Delta Flight 191 was dedicated at Dallas-Ft. Worth International Airport’s Founder’s Plaza. The crash occurred twenty-five years ago, August 2, 1985, at 6:06pm.

The Lockheed L-1011 departed Ft. Lauderdale enroute to Dallas and Los Angeles, but crashed short of the runway in a violent storm known as a microburst (a description of a microburst is here). One hundred thirty-seven passengers and crew lost their lives along with one motorist. A number of the survivors had life-altering injuries.  The stories of loss (for example, ) are simply overwhelming.

For the eight years prior to the Delta crash, there had been a fierce controversy within meteorology and aviation over Dr. Ted Fujita’s theory that an undiscovered atmospheric phenomena that he named a “downburst” had caused a string of jetliners, starting in 1973, to crash. As I explain in Warnings: The True Story of How Science Tamed the Weather, the consensus was that Dr. Fujita had misinterpreted what was actually occurring in these thunderstorms.
In spite of volumes of evidence in his book and in peer-reviewed papers, the consensus in meteorology was downbursts didn’t exist. 

After Delta 191 crashed, Dr. Fujita was brought in to investigate and, within a few months, found data that convinced even the doubters that downbursts (and their smaller version, microbursts) were mortal hazards to aircraft. Other investigations were also conducted including the National Transporation Safety Board’s and those of various attorneys retained by the airline, the government, and the victims. A messy, too-long trial followed the crash where people like Gene Skipworth, the air traffic controller who competently attempted to guide the flight to a safe landing, were dragged through the mud.

My copy of the National Transportation Safety Board’s final report on the crash. For the first time, the NTSB determined a microburst was a cause of a plane crash. 

With the benefit and perspective of time, we can look back and realize: For all of the tragedy of that evening and its immediate aftermath, a great deal of good has come out of the Delta crash.

Within two years, the Federal Aviation Adminstration had created a course to teach pilots to avoid downbursts and how to escape if they inadvertently flew into one. Ground-based low-level wind shear alert detection systems were installed at most major airports and Terminal Doppler Weather Radar was installed at 44 high-risk airports, including DFW. These two systems generate wind shear alerts that are relayed from the air traffic control tower to pilots in flight or preparing to take off. 

Since Delta, there has only been one microburst-related crash: USAir 1016 in Charlotte in 1994. For the last sixteen years, we have been crash-free. This triumph of science and technology has, based on my statistical analysis, prevented 16 crashes and saved well over 2,000 lives. Here’s an example:

On May 2, 2009, a downburst collapsed the Dallas Cowboys’ practice facility. The story was the lead on the national news for three days. But, from my perspective, the bigger news was what didn’t happen that day.

The Cowboy's collapsed practice facility. Courtesy:

This National Weather Service radar image shows the Cowboys’ microburst (deep red and purple colors) just northeast of the practice facility two minutes after the collapse:

This radar image, about thirteen minutes before the collapse, shows the downburst over the south part of Dallas-Ft. Worth International Airport (purple echo slightly down and left of center, near the tip of the shorter runway). Since it moved over the end of the runways, there is the likelihood that history would have repeated itself, but for the alarm systems.

But the planes and their passengers were safe, thanks to the pioneering work of Dr. Fujita (who passed away in 1998) and other courageous meteorologists who were willing to follow the science wherever it led, in spite of sometimes fierce criticism.

Twenty-five years later and we have safer take-offs and landings.  But for August 2nd, it is a day to remember the lost crew and passengers of Delta 191

With kind thoughts to the families of Flight 191,


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