What happened
During the arrival phase of flight, the aircrew observed thunderstorms to the west and southwest of the airport using both visual references and weather radar. Despite a special weather observation at 1636 containing thunderstorm information that was not noted by the crew, they elected to continue with an instrument landing system approach. By 1650, visibility had deteriorated significantly to one-quarter mile accompanied by heavy rain and hail. As the aircraft approached runway 21R, a severe level 4 thunderstorm moved from west to east over the northern part of the airport.
The air traffic controller provided wind information derived from the low-level wind shear alert system but used improper phraseology and failed to provide runway visual range information when visibility dropped below one mile. The crew struggled to interpret the wind shear data due to the volume and speed at which it was transmitted. At approximately 350 feet above ground level, the aircraft encountered low clouds, heavy rain, hail, and turbulence. The aircrew initiated a missed approach procedure.
During the go-around attempt, airspeed increased to 143 knots before dropping to approximately 119 knots. The captain determined that the aircraft would not be able to climb effectively and decided to land instead. The aircraft touched down about 2500 feet down the runway with the landing gear partially extended. It then slid for 3800 feet before leaving the runway surface. Wind conditions at the time were gusting up to 32 knots.
The investigation
The investigation focused on the operational decisions made during the approach and the effectiveness of communication regarding weather hazards. Key findings included the crew's failure to note critical weather updates and their difficulty in processing rapid wind shear alerts. The controller's improper phraseology and omission of visual range data were identified as contributing factors to the confusion.
Findings
Contributing factors to this accident included the decision to continue the approach into deteriorating weather conditions, the crew's inability to effectively manage the missed approach due to perceived performance limitations, and the partial extension of the landing gear. The severe weather environment, characterized by thunderstorms and wind shear, played a central role in the outcome.