Narrative:

The tower issued two low altitude alerts during practice instrument approaches. 1. The first alert was in the final phase of the GPS 32 approach. I had already broken out of the bases and was in visual conditions above the MDA with the runway in sight. The VASI indicated I was on the proper glide path. I did not understand why the alert was issued but initiated a climb and missed approach. 2. The second low altitude alert occurred on the next approach; my last of six that day. On the GPS 19 approach the tower issued the alert between as I was descending from 2;200 feet to 1;140 feet. I immediately began a climb and reached 1;500 feet right before I reached an intersection. I landed without incident. Upon landing I reviewed the approach chart and realized I had inadvertently started my altitude step downs one waypoint too soon. As a result I should have been at 2;200 feet and then started my decent to 1;140 feet. I had already started the decent to 1;140. In additional I realized during the final phase of the approach that I had descended below the circling minimums for the approach prior to landing on runway 32. I immediately corrected this error by climbing higher on downwind while circling.realizing the critical nature of my mistakes; I am scheduling additional refresher training with my cfii.

Google
 

Original NASA ASRS Text

Title: The pilot of a Cirrus SR-22 received an altitude alert for an unknown reason; which led to a missed approach. On the subsequent approach; ATC issued a second altitude alert due to the pilot's inadvertent premature descent.

Narrative: The tower issued two low altitude alerts during practice instrument approaches. 1. The first alert was in the final phase of the GPS 32 approach. I had already broken out of the bases and was in visual conditions above the MDA with the runway in sight. The VASI indicated I was on the proper glide path. I did not understand why the alert was issued but initiated a climb and missed approach. 2. The second low altitude alert occurred on the next approach; my last of six that day. On the GPS 19 approach the tower issued the alert between as I was descending from 2;200 feet to 1;140 feet. I immediately began a climb and reached 1;500 feet right before I reached an intersection. I landed without incident. Upon landing I reviewed the approach chart and realized I had inadvertently started my altitude step downs one waypoint too soon. As a result I should have been at 2;200 feet and then started my decent to 1;140 feet. I had already started the decent to 1;140. In additional I realized during the final phase of the approach that I had descended below the circling minimums for the approach prior to landing on runway 32. I immediately corrected this error by climbing higher on downwind while circling.Realizing the critical nature of my mistakes; I am scheduling additional refresher training with my CFII.

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.