August 2 marks the 25th anniversary of the crash of Delta 191, a Lockheed L-1011 TriStar, at Dallas Fort Worth. The accident claimed the lives of 164 people, including one person on the ground, but helped spur development of wind shear warning systems that are now a standard safety feature of today’s avionics suite.
The Dallas accident was one of three fatal wind shear events in the 70s and 80s which collectively became the catalyst for the invention of those technologies. The Delta crash was caused mainly by a powerful thunderstorm microburst-induced wind shear. These rare, but potentially deadly downdrafts, can strike the aircraft when it is at its most vulnerable in a low energy state on final approach.
On Wednesday I was heading back to California via DFW and took this photograph while on approach to runway 17L. As usual for a summer’s afternoon in Texas, the area was dotted with thunderstorms and this unusually powerful, isolated downpour caught my attention. As somebody who has followed the development of aviation safety systems, and who reported extensively on the development of wind shear detection and warning technology in the 1990s, I immediately thought of the 1985 crash near this spot, unaware of the approaching anniversary.
Downpour to the north of DFW. (Guy Norris)
This morning, on a completely unrelated matter, I happened to be e-mailing Gray Creech, who works in public affairs at NASA Dryden Flight Research Center. After some exchanges he mentioned that I might be interested to see a story commemorating the Delta 191 accident and the part NASA played in the subsequent technology development with its 737 research aircraft. More astonishingly it turns out that Gray was sitting in an aircraft by the active runway when the tragedy unfolded just a few feet away, and his comments are quoted in the piece.
NASA’s 737-130 research aircraft. Now retired, it is equally famous as the prototype Boeing 737. (NASA)