Narrative:

I descended below the assigned altitude on the frnch 3 arrival into den. We had multiple instructions; including heading; altitudes; and airspeed assignments in a short time period. I expect this coming into den but after 18 days off for vacation I was a little rusty on the quick changes in the box. We were asked to expedite our descent at one point so I selected level change. When level at 13;000 ft approach changed our runway assignment to the RNAV rnp 34R and cleared us to descend via the frnch 3 except maintain 13;000 ft until babaa. I knew we were getting close to babaa so I quickly tried to put in the RNAV to 34R. I mistakenly put in the RNAV GPS which explained why I could not find the transition fix. The first officer (first officer) was able to back me up and correct the error and selected the RNAV rnp and the correct transition fix. This took some time and I was now concerned I would miss the descent point for the SID so I reached up and selected VNAV and put in the lowest altitude on the STAR. However; I never put babaa as a hard 13;000 ft altitude. Babaa is a between 12;000 ft and 14;000 ft altitude normally. When I selected VNAV the aircraft started descending. In my rush to get everything loaded up I also forgot that we were given babaa at 13. I believe the first officer had a gut feeling that we needed to stay at 13 but with all the changes it was hard to keep it straight. The first officer asked ATC and ATC said 'if you are descending to 12;000 ft that is fine but 13;000 ft was the altitude until babaa.' in hindsight I could have done a better job distributing the workload. I could have asked the first officer to find and load up the approach while I concentrated on the arrival. Given the numerous instructions and late runway change; I felt we attempted to do a good job of vvmi but we missed the hard altitude assignment and programming at babaa.

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Original NASA ASRS Text

Title: B737-800 Captain reported overshooting a crossing altitude on the FRNCH 3 arrival into DEN; citing a late runway change as contributing.

Narrative: I descended below the assigned altitude on the FRNCH 3 Arrival into DEN. We had multiple instructions; including heading; altitudes; and airspeed assignments in a short time period. I expect this coming into DEN but after 18 days off for vacation I was a little rusty on the quick changes in the box. We were asked to expedite our descent at one point so I selected Level Change. When level at 13;000 ft approach changed our runway assignment to the RNAV RNP 34R and cleared us to descend via the FRNCH 3 except maintain 13;000 ft until BABAA. I knew we were getting close to BABAA so I quickly tried to put in the RNAV to 34R. I mistakenly put in the RNAV GPS which explained why I could not find the transition fix. The First Officer (FO) was able to back me up and correct the error and selected the RNAV RNP and the correct transition fix. This took some time and I was now concerned I would miss the descent point for the SID so I reached up and selected VNAV and put in the lowest altitude on the STAR. However; I never put BABAA as a hard 13;000 ft altitude. BABAA is a between 12;000 ft and 14;000 ft altitude normally. When I selected VNAV the aircraft started descending. In my rush to get everything loaded up I also forgot that we were given BABAA at 13. I believe the FO had a gut feeling that we needed to stay at 13 but with all the changes it was hard to keep it straight. The FO asked ATC and ATC said 'if you are descending to 12;000 ft that is fine but 13;000 ft was the altitude until BABAA.' In hindsight I could have done a better job distributing the workload. I could have asked the FO to find and load up the approach while I concentrated on the arrival. Given the numerous instructions and late runway change; I felt we attempted to do a good job of VVMI but we missed the hard altitude assignment and programming at BABAA.

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.