EA32 CREW SET 3000 FT IN ALT SELECT WHEN DSNDING TO A 5431 FT ARPT.

Narrative

ACFT LEVEL AT 13000 FT. CLRNC GIVEN AGAIN TO MAINTAIN 13000 FT. I HEARD 3000 FT AND LOOKED AT ALT. SINCE ACFT WAS ALREADY AT 13000 FT I THOUGHT THE CLRNC WAS 3000 FT AND STARTED DOWN. I WAS PREOCCUPIED WITH THE FO IN TRYING TO FIGURE THE DIFFERENCE IN THE APCH IN THE COMMERCIAL CHART VERSUS THE APCH IN THE DATABASE. BOTH CREW MEMBERS WERE IN A HVY WORKLOAD AND BOTH MISSED THE CORRECT CLRNC. I KNEW DEN WAS 5000 FT; BUT BEFORE I STOPPED; THE CTLR ASKED OUR ALT. IT WAS 11000 FT AND HE SAID THAT WOULD BE ALL RIGHT. WE MAINTAINED 11000 FT AND CONTINUED ON VECTORS FOR THE APCH AND LANDED. FACTORS: 1) BOTH PLTS FAIRLY NEW IN GLASS COCKPIT. 2) LATE HR AND WX -- FATIGUE WITH HVY COCKPIT LOAD. 3) UNFAMILIAR WITH DEN ARPT AND APCHS AND PROCS. 4) PLTS DID NOT CONFIRM ALT CHANGE WITH EACH OTHER. COMPANY POLICY AND PROCS FOLLOWED TO THE LETTER WOULD PROBABLY HAVE CAUGHT THE MISTAKE. LESSONS: 1) ONE PLT MUST ALWAYS FLY THE AIRPLANE. 2) NEVER GET TOO PREOCCUPIED INSIDE ACFT WITH GLASS PANEL. 3) ALWAYS CONFIRM ALT CLRNC WITH OTHER PLT. IF UNSURE; ASK CTLR FOR VERIFICATION.