On August 2, 1985, Delta Air Lines Flight 191 crashed while attempting to land at Dallas/Fort Worth International Airport, claiming 137 lives. The tragedy exposed a deadly, invisible atmospheric phenomenon known as a microburst, changing how commercial aviation handles severe weather forever.
The Lockheed L-1011 TriStar encountered violent, localized downdrafts right on its final approach. While standard weather radar could detect heavy rain, the technology of the era couldn't spot the rapid shifts in wind speed and direction that threw the aircraft completely out of control.
The Anatomy of a Microburst
A microburst is a small-scale column of sinking air that crashes down from a thunderstorm cloud and spreads out rapidly in all directions upon hitting the ground. When an airplane flies through this invisible trap, it experiences a sudden, brutal sequence of changes in performance.
First, the aircraft flies into a strong headwind, which causes a sharp spike in airspeed and lifts the plane above its normal glide slope. Unaware that a downdraft is waiting, a pilot will typically reduce power and lower the nose to compensate. Moments later, the plane passes through the core of the downdraft, plunging downward. Finally, as it exits the microburst, the headwind turns into an extreme tailwind. If you want more about the background of this, Associated Press provides an in-depth summary.
The plane loses its lifting force almost instantly. Without advanced warning or high-energy altitude reserves, a heavy commercial airliner cannot recover quickly enough. This exact mechanism caught Flight 191 just as it dropped below 1,000 feet.
Sequence of Events on Flight 191
Flight 191 was a scheduled routine journey from Fort Lauderdale, Florida, to Los Angeles, California, with an intermediate stop at Dallas/Fort Worth (DFW). As the flight approached Texas, a thunderstorm cell began developing directly along their assigned arrival path.
- 17:51 CDT: The flight crew notices rain activity ahead near Fort Worth and discusses the weather.
- 17:52 CDT: The flight contacts DFW Approach Control and receives terminal information indicating potential showers.
- 18:03 CDT: Controllers instruct the crew to reduce speed to 150 knots as they line up for Runway 17L.
- 18:05:36 CDT: Captain Edward Connors shouts, "Hang on to the son of a bitch!" as severe wind shear slams the aircraft downward.
The TriStar sank rapidly below the glide slope, striking the ground in an open field more than a mile short of the runway threshold. It bounced, sheared across Texas State Highway 114—striking a vehicle and killing the driver—and slammed into a massive airport water tank. The ensuing fire destroyed most of the fuselage. Of the 163 people on board, 134 passengers and crew died, along with the motorist on the highway.
Findings of the National Transportation Safety Board
The National Transportation Safety Board (NTSB) launched an extensive investigation into the disaster. The final report pointed to a combination of environmental and human factors rather than a single mechanical failure.
The primary culprit was the microburst-induced severe wind shear. However, the NTSB also criticized the lack of adequate training and procedural guidance for pilots dealing with low-altitude wind shear. Furthermore, meteorological tools at the time failed to give real-time hazard warnings to air traffic controllers or flight crews.
You can read more about historical safety oversight updates through the Federal Aviation Administration.
Lasting Safety Transformations
The disaster forced the aviation industry to rethink weather safety from the ground up. Regulators and manufacturers collaborated to develop new technology that saves thousands of lives today.
- Onboard Radar: Airlines installed predictive wind shear detection systems directly into aircraft cockpits, giving pilots visual and aural warnings well before entering a hazard zone.
- Ground-Based Sensors: The installation of Terminal Doppler Weather Radar (TDWR) and Low Level Windshear Alert Systems (LLWAS) at major airports vastly improved monitoring capabilities.
- Pilot Training: Simulator training programs were overhauled to teach escape maneuvers for sudden wind shear, emphasizing immediate maximum thrust and maintaining pitch attitude over altitude recovery.
Frequently Asked Questions
What caused Delta Flight 191 to crash?
The crash was caused by a microburst—a severe downdraft from a localized thunderstorm—that produced extreme wind shear and stripped the aircraft of its lift during final approach.
How many people survived the disaster?
Out of 163 people on board, 27 people (24 passengers and 3 crew members) survived the crash. One person on the ground was also killed when the aircraft struck a vehicle on a highway.
What aircraft model was Flight 191?
The aircraft was a Lockheed L-1011 TriStar, a wide-body, three-engine jetliner powered by Rolls-Royce engines.
Did the accident change aviation laws?
Yes. It led to mandatory wind shear training for all commercial pilots and the nationwide implementation of advanced ground and airborne weather radar systems.
