Narrative:

On final to runway 28R into sfo we received a low altitude alert from tower. We were approximately 400 feet below the VNAV path. As pilot monitoring (pm); I had been distracted by another aircraft on final for 28L. The captain (ca) had been concerned about being too high and fast on the FMS bridge visual and I believe through accident use of flch and speed intervene; he commanded the aircraft to go too low (and I failed to monitor the situation properly. I perceived we were low; but thought it was part of his plan; until we received the alert from ATC (about 3 miles out at around 600').

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Original NASA ASRS Text

Title: Air carrier flight crew reported receiving a 'low altitude alert' from tower on VNAV approach into SFO.

Narrative: On final to Runway 28R into SFO we received a low altitude alert from tower. We were approximately 400 feet below the VNAV path. As Pilot Monitoring (PM); I had been distracted by another Aircraft on final for 28L. The Captain (CA) had been concerned about being too high and fast on the FMS bridge visual and I believe through accident use of FLCH and speed intervene; he commanded the Aircraft to go too low (and I failed to monitor the situation properly. I perceived we were low; but thought it was part of his plan; until we received the alert from ATC (about 3 miles out at around 600').

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.