What happened
During the arrival phase, onboard radar detected thunderstorms in the vicinity of the airport. As the flight continued, the Automatic Terminal Information System (ATIS) information changed. When the pilots contacted Washington Approach Control using outdated ATIS data, the controller did not correct the information. The crew was advised of heavy rain, strong winds, and a pilot report of wind shear near the airport, but they were not informed that the Low Level Wind Shear Alert System (LLWAS) was inoperative.
The flight was vectored for a Rosslyn Runway 18 approach. After contacting the tower, the pilots were advised that the wind was from 230 degrees at 35 to 45 knots. Shortly thereafter, on final approach, the aircraft was inundated by rain. The crew lost sight of the airport, began a missed approach, and encountered large hail and moderate turbulence. During the missed approach, the aircraft stopped climbing at approximately 600 feet, and the speed slowed from 170 to 138 knots. The captain applied full power, and the aircraft responded, but the N1 and Exhaust Gas Temperature (EGT) limits were exceeded. The captain reduced power and diverted to Dulles International Airport.
The investigation
A post-flight examination revealed that the first and second stage turbine blades of all three engines had been overtempered.