Narrative:

I was performing as first officer on a flight into ZZZ. The flight was uneventful up until the final approach into ZZZ. The captain was pilot flying and had chosen to fly a practice category III approach to an autoland. The appropriate items were briefed and the aircraft was set up to perform the approach. All indications were normal with 'land 3' annunciated. Aircraft systems functioned normally until 'rollout' capture. At 'rollout' capture and above 5 ft from the runway; the aircraft yawed about 30 degrees right. The captain disconnected the autopilot and flew the aircraft back toward the center of the runway. The captain was able to bring the aircraft to a stop on runway xxl. At this point; both the captain and I thought we might have momentarily departed the runway surface. We elected to clear the runway; stop on the taxiway; and have the fire chief and maintenance check the right main landing gear and engine for damage. After the ground personnel checked the aircraft and no damage was found; we were given the ok to taxi to the gate. Taxi to the gate was uneventful. Concerns: had this been in actual category III weather; a go around would have been attempted. At 30 degrees angle off to the runway; if we were lucky enough to get airborne before departing the runway; the aircraft vector would have taken it across the 2 other runways and toward the mountains to the east. Lesson learned: always monitor and be ready to take control over the automatic flight systems. The quick and appropriate actions taken by the captain prevented a potential accident. Callback conversation with reporter revealed the following information: initial inspection by maintenance could find no anomalies when the system was tested. Subsequent tests did reveal problems with the system but nothing that might have caused the dramatic yaw. The auto land system is designed and the reporter was trained to expect the system to be fail passive at this low altitude. The incident has been reported to the air carrier safety committee and has generated a great deal of interest and concern. The aircraft manufacturer has also been contacted.

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Original NASA ASRS Text

Title: B757 First Officer reports a dramatic yaw to the right during auto land flare. Captain is able to disconnect the autopilot and land the aircraft safely.

Narrative: I was performing as First Officer on a flight into ZZZ. The flight was uneventful up until the final approach into ZZZ. The Captain was Pilot Flying and had chosen to fly a practice Category III approach to an autoland. The appropriate items were briefed and the aircraft was set up to perform the approach. All indications were normal with 'Land 3' annunciated. Aircraft systems functioned normally until 'rollout' capture. At 'rollout' capture and above 5 FT from the runway; the aircraft yawed about 30 degrees right. The Captain disconnected the autopilot and flew the aircraft back toward the center of the runway. The Captain was able to bring the aircraft to a stop on Runway XXL. At this point; both the Captain and I thought we might have momentarily departed the runway surface. We elected to clear the runway; stop on the taxiway; and have the Fire Chief and Maintenance check the right main landing gear and engine for damage. After the ground personnel checked the aircraft and no damage was found; we were given the OK to taxi to the gate. Taxi to the gate was uneventful. Concerns: Had this been in actual Category III weather; a go around would have been attempted. At 30 degrees angle off to the runway; if we were lucky enough to get airborne before departing the runway; the aircraft vector would have taken it across the 2 other runways and toward the mountains to the east. Lesson learned: Always monitor and be ready to take control over the automatic flight systems. The quick and appropriate actions taken by the Captain prevented a potential accident. Callback conversation with Reporter revealed the following information: Initial inspection by maintenance could find no anomalies when the system was tested. Subsequent tests did reveal problems with the system but nothing that might have caused the dramatic yaw. The auto land system is designed and the reporter was trained to expect the system to be fail passive at this low altitude. The incident has been reported to the air carrier safety committee and has generated a great deal of interest and concern. The aircraft manufacturer has also been contacted.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.