1985-08-02
Delta Air Lines
Flight DL191
Departure
Fort Lauderdale-Hollywood International Airport, Fort Lauderdale, USA
Destination
Dallas/Fort Worth International Airport, Dallas, USA
Causation Breakdown
Recurrence Likelihood Today
Low
Predictive wind shear detection systems are now mandatory on commercial aircraft. Doppler radar at airports provides real-time microburst alerts. Wind shear escape maneuver training is universal. Crew decision-making to avoid thunderstorms has been reinforced in standard operating procedures.
Summary
Delta 191 encountered a catastrophic microburst on final approach to Dallas/Fort Worth. The crew had chosen to fly through a visible thunderstorm, and the microburst's rapid sequence of headwind, downdraft, and tailwind reduced lift faster than recovery was possible. Of 163 aboard, 136 died, along with 1 person on the ground. The accident transformed the aviation industry's approach to wind shear detection and avoidance training.
Cause & Investigation
Determined cause
Wind shear — microburst encounter on approach
The L-1011 flew through a visible thunderstorm cell on approach to Dallas/Fort Worth and encountered a severe microburst. The aircraft first experienced a strong headwind increasing airspeed, then a violent downdraft, then a tailwind that reduced lift catastrophically. The aircraft lost over 100 knots of airspeed within seconds, struck the ground short of the runway, bounced, hit a vehicle on a highway, and struck two water storage tanks.
Investigation body
National Transportation Safety Board (NTSB), USA.
Timeline & Safety Improvements
Flight DL191 disaster
Lockheed L-1011-385 TriStar operating for Delta Air Lines. 137 fatalities, 27 survivors.
Formal investigation opened
Conducted by: National Transportation Safety Board (NTSB), USA.
Cause determined: Wind shear — microburst encounter on approach
The L-1011 flew through a visible thunderstorm cell on approach to Dallas/Fort Worth and encountered a severe microburst. The aircraft first experienced a strong headwind increasing airspeed, then a violent downdraft, then a tailwind that reduced lift catastrophically. The aircraft lost over 100 knots of airspeed within seconds, struck the ground short of the runway, bounced, hit a vehicle on a highway, and struck two water storage tanks.
Improvement implemented
Low-level wind shear alert systems (LLWAS) were installed at major U.S. airports.
Improvement implemented
Doppler weather radar became mandatory at all major airports to detect microbursts.
Improvement implemented
Wind shear recognition and escape maneuver training became mandatory for all commercial pilots.
Improvement implemented
The FAA accelerated development of onboard wind shear detection systems (predictive WSAS).