Narrative:

While conducting an instrument approach into ZZZ late at night (early morning); I inadvertently descended below the minimum altitude for the approach segment by about 250 ft. I was flying with another pilot who was working radios while I was flying. We had completed a procedure turn and advised the controller that we were established inbound. Normally; ZZZ1 TRACON is the facility that we work with when operating at ZZZ; but since it was late; they were closed and we were talking to ZZZ2 TRACON. The controller cleared us for the approach; and as we crossed the IAF I began a descent to 2;800 - the minimum altitude for that segment of the approach. As we were descending; there was some confusion between myself and the pilot I was flying with as to if the controller wanted us to change frequencies and how he wanted us to cancel our IFR clearance. This confusion caused me to break my instrument scan to discuss with the other pilot and as he queried the controller. I think since we weren't in the clouds; I was slightly less focused on keeping my scan going. After a few seconds; my normal scan resumed and I noticed we were approximately 250 ft. Below the minimum altitude for that segment of the approach. Upon seeing this I immediately began a climb back to 2800 and leveled off. The rest of the approach to landing continued without further issue. The cause of this problem was confusion regarding ATC instructions which caused me to break my scan and continue a descent past the minimum altitude. As PIC (pilot in command); I felt a responsibility to be involved in the communication issue; when I should have delegated it to the other pilot (who is fully qualified).

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Original NASA ASRS Text

Title: C172 pilot became distracted on approach and descended below minimum altitude.

Narrative: While conducting an instrument approach into ZZZ late at night (early morning); I inadvertently descended below the minimum altitude for the approach segment by about 250 ft. I was flying with another pilot who was working radios while I was flying. We had completed a procedure turn and advised the controller that we were established inbound. Normally; ZZZ1 TRACON is the facility that we work with when operating at ZZZ; but since it was late; they were closed and we were talking to ZZZ2 TRACON. The controller cleared us for the approach; and as we crossed the IAF I began a descent to 2;800 - the minimum altitude for that segment of the approach. As we were descending; there was some confusion between myself and the pilot I was flying with as to if the controller wanted us to change frequencies and how he wanted us to cancel our IFR clearance. This confusion caused me to break my instrument scan to discuss with the other pilot and as he queried the controller. I think since we weren't in the clouds; I was slightly less focused on keeping my scan going. After a few seconds; my normal scan resumed and I noticed we were approximately 250 ft. below the minimum altitude for that segment of the approach. Upon seeing this I immediately began a climb back to 2800 and leveled off. The rest of the approach to landing continued without further issue. The cause of this problem was confusion regarding ATC instructions which caused me to break my scan and continue a descent past the minimum altitude. As PIC (Pilot in Command); I felt a responsibility to be involved in the communication issue; when I should have delegated it to the other pilot (who is fully qualified).

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.