A DSNDING CPR CL601 OVERSHOOTS ITS ASSIGNED ALT WHILE THE CAPT; PF; IS HANDLING THE RADIOS AS WELL. FO WAS OFF ON #2 RADIO.

Narrative

AT APPROX PM00 ON FEB/XA/99; WE WERE FLYING AT 14000 FT SW ON V378 ENRTE TO DCA. WE WERE IN MODERATE TURB; HVY RAIN; AND SCANNING THE RADAR FOR POSSIBLE TSTMS. MY COPLT WAS OBTAINING THE ATIS AT DCA; I WAS HANDLING THE RADIOS. ON THE DSCNT; AS I WAS PASSING BY 9700 FT AND LOOKED AT THE ALT SELECT; IT WAS STILL AT 14000 FT. I KNEW WE WERE CLR FOR DSCNT BUT WE BOTH WERE CONFUSED AS TO WHAT THE ASSIGNED ALT WAS. I CALLED TO VERIFY AND ATC SAID 10000 FT. ATC SAW THAT WE PASSED BY 10000 FT. HE CLRED US TO 8000 FT. I BELIEVE THAT THERE IS NO EXCUSE FOR ALT BUSTING BUT THERE ARE TIMES WHEN BOTH PLTS FALL OUT OF THE LOOP. THIS IS THE CASE HERE. I THINK COMBINATIONS OF THE WX; TURB; ETC; AND MAYBE FATIGUE; SINCE WE WERE ON DUTY SINCE AM00 AND THIS WAS THE 4TH LEG; WERE FACTORS. WE WERE SCHEDULED TO CONTINUE ON TO TEB BUT DID ELECT TO STAY OVERNIGHT AT DCA BECAUSE IT WAS TURNING INTO A LONG DAY. I BELIEVE WHEN ATC GIVES CLRNCS BOTH PLTS HAVE TO AGREE ON WHAT IT WAS AND MONITOR THE PROGRESS. WITH 1 PLT OUT OF THE LOOP MAKING A PHONE CALL; GETTING ATIS OR WHATEVER IT MAY BE; YOU MUST STAY IN THE LOOP. FOOD FOR THOUGHT AND ACTION.