Narrative:

Descending from 13000 ft to 7000 ft, I received a clearance to continue descending to 4200 ft. Descending through 3500 ft, I discovered the altitude deviation. Just as I was transitioning to a climb, ZME told me to maintain 3500 ft. I mainly contribute my altitude deviation from being distraction by the passenger riding in the copilot seat. I will in the future emphasize on my briefings to the passenger that no conversation will be done below 10000 ft. Other factors that also may have contributed to the occurrence are that I just received my part 135 check ride the day before in the C414, and hadn't flown this plane for some time. The C90 king air I usually fly has an altitude alerter.

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Original NASA ASRS Text

Title: AIR TAXI PLT DSNDS BELOW ASSIGNED ALT WHEN DISTR BY PAX.

Narrative: DSNDING FROM 13000 FT TO 7000 FT, I RECEIVED A CLRNC TO CONTINUE DSNDING TO 4200 FT. DSNDING THROUGH 3500 FT, I DISCOVERED THE ALTDEV. JUST AS I WAS TRANSITIONING TO A CLB, ZME TOLD ME TO MAINTAIN 3500 FT. I MAINLY CONTRIBUTE MY ALTDEV FROM BEING DISTR BY THE PAX RIDING IN THE COPLT SEAT. I WILL IN THE FUTURE EMPHASIZE ON MY BRIEFINGS TO THE PAX THAT NO CONVERSATION WILL BE DONE BELOW 10000 FT. OTHER FACTORS THAT ALSO MAY HAVE CONTRIBUTED TO THE OCCURRENCE ARE THAT I JUST RECEIVED MY PART 135 CHK RIDE THE DAY BEFORE IN THE C414, AND HADN'T FLOWN THIS PLANE FOR SOME TIME. THE C90 KING AIR I USUALLY FLY HAS AN ALT ALERTER.

Data retrieved from NASA's ASRS site as of July 2007 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.