Investigation Summary
The investigation focused on the phenomenon of microbursts, which were not well understood by flight crews at the time. A critical factor in the crew's decision to continue was that a Boeing 727 had successfully landed on the same runway just moments before Flight 191, providing a false sense of safety. As Flight 191 entered a rain shaft beneath a developing cumulonimbus cloud, it first experienced an increase in airspeed due to a headwind, which the pilot countered by reducing thrust. Moments later, the aircraft was hit by a powerful downdraft and a sudden tailwind. This wind shear caused the airspeed to drop precipitously. Despite the crew applying full power, the aircraft's high sink rate could not be arrested in time. The NTSB highlighted that the crew lacked definitive, real-time wind shear hazard information and that the airport's Low Level Wind Shear Alert System (LLWAS) was insufficient for detecting microbursts occurring away from its sensors.
Final Conclusions
The NTSB determined the probable causes were the flightcrew's decision to initiate and continue the approach into a cumulonimbus cloud containing visible lightning; the lack of specific guidelines and training for avoiding low-altitude wind shear; and the lack of real-time wind shear hazard information. The encounter with a microburst-induced severe wind shear at low altitude was the terminal event.
Video Analysis
Delta Air Lines Flight 191: Microburst and Wind Shear at DFW — This video examines the 1985 crash of a Lockheed L-1011 TriStar at Dallas/Fort Worth International Airport caused by a severe microburst, leading to major changes in wind shear detection technology.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Crew Experience
Captain
Edward Michael Connors Jr., aged 57. Had been with Delta since 1954.
First Officer
Rudolph Przydzial Price Jr., aged 42. Had been with Delta since 1970.
Flight Engineer
Nicholas Nestor Nassick, aged 43. Had been with Delta since 1976.
Systems & Failure Modes
LLWAS
Low Level Wind Shear Alert System; the ground-based sensors at DFW failed to detect the microburst in time because the storm was centered between sensors.
GPWS
Ground Proximity Warning System; provided a 'Pull Up' warning 8 seconds before the initial impact.
Weather Radar
Onboard monochromatic radar was unable to distinguish the intensity of the microburst within the rain shaft.
Interesting Facts
- 01The accident led to the mandatory installation of airborne wind shear detection and alert systems on all commercial aircraft.
- 02One person on the ground, the driver of a car on Highway 114, was killed during the impact sequence.
- 03The aircraft was a Lockheed L-1011 TriStar, which was one of the most advanced wide-body jets of its era.
- 0429 people survived the crash, most of whom were seated in the aft section of the fuselage which remained relatively intact.
- 05The microburst produced a wind velocity change of approximately 50 knots and a downdraft of over 3,000 feet per minute.
Safety Actions & Advisories
Terminal Doppler Weather Radar (TDWR)
The FAA accelerated the development and deployment of TDWR at major airports to provide high-resolution detection of microbursts and wind shear.
Predictive Wind Shear Systems
Mandated the development of airborne systems that could predict wind shear ahead of the aircraft rather than just reacting to it.
Wind Shear Training
Standardized pilot training for wind shear recovery, emphasizing the 'Wind Shear Escape Manoeuvre' (maximum thrust and pitch).
Location
ACCIDENT SITE · Coordinates taken from the wikidata coordinate.