Narrative:

We were on descent and vectors for visual approach to runway 35R as prescribed by ATC. Our assigned altitude was 13000 ft. As we were descending out of approximately 14500 ft, approach control changed our runway to runway 35L visual. Upon acknowledgement by the first officer, I commenced another approach briefing and asked the so for another 'approach check.' these company required briefs and checklists had already been completed for runway 35R when we were descending out of FL180. Our company procedures require a new approach briefing and approach check in the event of a runway change. I had begun hand flying when we were descending out of approximately 17000 ft MSL and soon after, was issued a clearance of heading 330 degrees and descent to 13000 ft MSL. The change of runway came at approximately 14500 ft MSL and since the WX was so good, and I did have the airport in sight, I gave the quick approach brief (runway 35L) while still hand flying. The 3 of us became somewhat preoccupied with our various duties and checks, and I don't believe the altitude calls were made as we approached our assigned altitude of 13000 ft. Upon completion (so stating) of the second 'approach check' I became more focused on the business of flying the aircraft, and noticed our altitude was now 12400 ft MSL! I immediately added power smoothly and corrected back to 13000 ft MSL. Our rates of descent and then climb during this altitude excursion were never greater than 1000 FPM. In hindsight, I should have reconnected the autoplt upon runway change, and used better overall workload management to accomplish our tasks. The timing of the ATC runway change could not come at a worse time.

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Original NASA ASRS Text

Title: B737 OVERSHOOTS ASSIGNED ALT FOLLOWING LAST MIN RWY CHANGE DEN.

Narrative: WE WERE ON DSCNT AND VECTORS FOR VISUAL APCH TO RWY 35R AS PRESCRIBED BY ATC. OUR ASSIGNED ALT WAS 13000 FT. AS WE WERE DSNDING OUT OF APPROX 14500 FT, APCH CTL CHANGED OUR RWY TO RWY 35L VISUAL. UPON ACKNOWLEDGEMENT BY THE FO, I COMMENCED ANOTHER APCH BRIEFING AND ASKED THE SO FOR ANOTHER 'APCH CHK.' THESE COMPANY REQUIRED BRIEFS AND CHKLISTS HAD ALREADY BEEN COMPLETED FOR RWY 35R WHEN WE WERE DSNDING OUT OF FL180. OUR COMPANY PROCS REQUIRE A NEW APCH BRIEFING AND APCH CHK IN THE EVENT OF A RWY CHANGE. I HAD BEGUN HAND FLYING WHEN WE WERE DSNDING OUT OF APPROX 17000 FT MSL AND SOON AFTER, WAS ISSUED A CLRNC OF HDG 330 DEGS AND DSCNT TO 13000 FT MSL. THE CHANGE OF RWY CAME AT APPROX 14500 FT MSL AND SINCE THE WX WAS SO GOOD, AND I DID HAVE THE ARPT IN SIGHT, I GAVE THE QUICK APCH BRIEF (RWY 35L) WHILE STILL HAND FLYING. THE 3 OF US BECAME SOMEWHAT PREOCCUPIED WITH OUR VARIOUS DUTIES AND CHKS, AND I DON'T BELIEVE THE ALT CALLS WERE MADE AS WE APCHED OUR ASSIGNED ALT OF 13000 FT. UPON COMPLETION (SO STATING) OF THE SECOND 'APCH CHK' I BECAME MORE FOCUSED ON THE BUSINESS OF FLYING THE ACFT, AND NOTICED OUR ALT WAS NOW 12400 FT MSL! I IMMEDIATELY ADDED PWR SMOOTHLY AND CORRECTED BACK TO 13000 FT MSL. OUR RATES OF DSCNT AND THEN CLB DURING THIS ALT EXCURSION WERE NEVER GREATER THAN 1000 FPM. IN HINDSIGHT, I SHOULD HAVE RECONNECTED THE AUTOPLT UPON RWY CHANGE, AND USED BETTER OVERALL WORKLOAD MGMNT TO ACCOMPLISH OUR TASKS. THE TIMING OF THE ATC RWY CHANGE COULD NOT COME AT A WORSE TIME.

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.