Narrative:

I was the non-flying pilot on this leg. We were on the FMS bridge 28R visual at sfo. The approach controller issued instructions for us to change over to runway 28L after passing the san mateo bridge. At the bridge (approximately 1300 AGL); I changed the mcdu flight plan page over to 28L; and the tower controller called then and asked if we acknowledge our clearance to land. After responding affirmative; the captain called for flaps full; and I completed the landing checklist after verifying the flaps were at the full configuration. From the bridge until this point I was heads down as events were happening quickly; and I was operating in the yellow as I was not effectively monitoring outside situational events. When I did look up; I noticed the VASI was red over red; and we were at approximately 600 AGL. Before I could call this out; the tower called with a low altitude alert just as the captain began leveling off. We then intercepted the VASI glidepath and landed.when the mcdu was changed from 28R to 28L; descent mode went from managed to vertical speed. With the ensuing distractions (controller query; configuration change; remainder of checklist reading); neither myself nor the captain were immediately aware of the vertical speed mode. The longer flight path to runway 28L resulted in a vertical path below the VASI path. Either an earlier final configuration setup; or not going heads down near 1000 AGL to make a change in the mcdu would have helped to avoid this situation.

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Original NASA ASRS Text

Title: A321 flight crew reported getting low on a visual approach to SFO after a late runway change resulting in high workload and distractions.

Narrative: I was the non-flying pilot on this leg. We were on the FMS bridge 28R visual at SFO. The approach controller issued instructions for us to change over to runway 28L after passing the San Mateo bridge. At the bridge (approximately 1300 AGL); I changed the MCDU flight plan page over to 28L; and the tower controller called then and asked if we acknowledge our clearance to land. After responding affirmative; the Captain called for flaps full; and I completed the landing checklist after verifying the flaps were at the full configuration. From the bridge until this point I was heads down as events were happening quickly; and I was operating in the yellow as I was not effectively monitoring outside situational events. When I did look up; I noticed the VASI was red over red; and we were at approximately 600 AGL. Before I could call this out; the tower called with a low altitude alert just as the Captain began leveling off. We then intercepted the VASI glidepath and landed.When the MCDU was changed from 28R to 28L; descent mode went from managed to vertical speed. With the ensuing distractions (controller query; configuration change; remainder of checklist reading); neither myself nor the Captain were immediately aware of the vertical speed mode. The longer flight path to runway 28L resulted in a vertical path below the VASI path. Either an earlier final configuration setup; or not going heads down near 1000 AGL to make a change in the MCDU would have helped to avoid this situation.

Data retrieved from NASA's ASRS site 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.