ACR OVERSHOOTS ASSIGNED ALT ON ARR NEAR MSP WHEN CREW BECOMES TASK SATURATED.

Narrative

ON DSCNT ON THE BAE.EAU4.MSP ARR WE WERE CLRED TO CROSS TWINZ AT 11000 FT. PASSING 18000 FT THE FO WAS DOING THE DSCNT CHK. PART OF THIS CHKLIST IS FOR HIM TO MAKE A PA. THE FO IS FAIRLY NEW TO THE COMPANY AND WAS SLOW TO COMPLETE THE CHKLIST. I WAS FLYING. ATC HAD ASSIGNED US 290 KTS. I SAW THAT WE WOULD BE TIGHT ON THE XING RESTR AND HAD DEPLOYED THE SPOILERS TO INCREASE VERT SPD. I WAS NOW DOING THESE TASKS. USING BOTH HANDS TO CTL VERT SPD AND DEPLOY/CTL/RETRACT THE SPOILERS. WATCHING MI ON DME TO TWINZ. COMPUTING DSCNT RATE/MI TO GO. MAINTAINING AIRSPD 290 KTS. LOOKING UP AND SETTING THE NEW VOR FREQ AND COURSE. (TWINZ IS ON THE DOGLEG CHANGEOVER POINT.) CHANGING COM FREQ DUE TO ATC HDOF. WITH ALL OF THIS GOING ON WITHOUT THE FO'S ALT AWARENESS CALLS; I SIMPLY WAS LATE ON MY SCAN FOR LEVELOFF. I WAS TASK SATURATED AND ALLOWED THE INCIDENT TO HAPPEN. AFTER REVIEWING THE EVENT; I NOW REALIZE THAT DIRECTION AND ALT MUST HAVE A SUPER PRIORITY IN MY SCAN. THE ACFT DSNDED TO 10500 FT AND I RETURNED (CLBED) BACK TO 11000 FT. THERE WASN'T ANY SEPARATION CONFLICTS. SUPPLEMENTAL INFO FROM ACN 466267: AS I PUT AWAY THE PA HANDSET; I NOTICED HE WAS PASSING THROUGH ABOUT 10800 FT MSL DSNDING. I LOOKED AT THE ALT WINDOW AND SAW 11000 FT. I ASKED WHAT WE WERE CLRED TO AND HE REALIZED THAT WAS CLRED TO 11000 FT AS I STATED WE WERE GOING BELOW 11000 FT. HE STOPPED THE DSCNT AT ABOUT 10500 FT AND WE CLBED BACK UP TO 11000 FT. I BELIEVE WE MIGHT HAVE BEEN TASK SATURATED FOR A BRIEF PERIOD WHICH ALLOWED THIS DEV TO OCCUR. WE STRESS 'FLY THE AIRPLANE' 3 TIMES; AND WE CONSTANTLY NEED TO REMIND OURSELVES OF THAT RULE. IT'S THE BOTTOM LINE.