Narrative:

Just outside the FAF with an altitude intercept of 2000 feet; and a FAF crossing of at or above 1700 feet; the tower cleared us to land at the same time the VNAV indicator rapidly descended and my first officer (first officer) said 'there is your five-mile point' which I should have been at 1700 feet instead of the 2000 feet I was at. I thought I was fairly high and over responded by going vertical speed and blindly entering two scrolls down; which unbeknownst to me resulted in a 4100 fpm descent rate putting us below the crossing altitude of 1700 feet or above. We ended up at just over 1400 feet as I quickly tried to recover manually. Then we received the low altitude alert from the tower and continued to recover back to the glideslope; landing without further incident. I should have entered 1700 feet in the preselect altitude when cleared to land and then the automation would have worked fine. I also should have visually verified my V/south input; I would never purposefully select 4100 feet; especially that low. My first officer also had just entered a five-mile circle without telling me ahead of time; I thought we were at the five-mile point and therefore too high; when he said there is your five-mile point; along with the rapidly descending slope indicator. What my first officer was meaning; and just wanting to help; is that he had just entered a five-mile fix circle; not that we were at the five-mile point.

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Original NASA ASRS Text

Title: B737 flight crew reported a communications breakdown between Captain and First Officer regarding approach clearance resulted in an altitude deviation and low altitude alert.

Narrative: Just outside the FAF with an altitude intercept of 2000 feet; and a FAF crossing of at or above 1700 feet; the Tower cleared us to land at the same time the VNAV indicator rapidly descended and my FO (First Officer) said 'There is your five-mile point' which I should have been at 1700 feet instead of the 2000 feet I was at. I thought I was fairly high and over responded by going Vertical Speed and blindly entering two scrolls down; which unbeknownst to me resulted in a 4100 fpm descent rate putting us below the crossing altitude of 1700 feet or above. We ended up at just over 1400 feet as I quickly tried to recover manually. Then we received the low altitude alert from the Tower and continued to recover back to the glideslope; landing without further incident. I should have entered 1700 feet in the preselect altitude when cleared to land and then the automation would have worked fine. I also should have visually verified my V/S input; I would never purposefully select 4100 feet; especially that low. My FO also had just entered a five-mile circle without telling me ahead of time; I thought we were at the five-mile point and therefore too high; when he said there is your five-mile point; along with the rapidly descending slope indicator. What my FO was meaning; and just wanting to help; is that he had just entered a five-mile fix circle; not that we were at the five-mile point.

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.