Narrative:

At approximately PM00 on feb/xa/99, we were flying at 14000 ft southwest on V378 en route to dca. We were in moderate turbulence, heavy rain, and scanning the radar for possible thunderstorms. My copilot was obtaining the ATIS at dca, I was handling the radios. On the descent, as I was passing by 9700 ft and looked at the altitude select, it was still at 14000 ft. I knew we were clear for descent but we both were confused as to what the assigned altitude was. I called to verify and ATC said 10000 ft. ATC saw that we passed by 10000 ft. He cleared us to 8000 ft. I believe that there is no excuse for altitude busting but there are times when both pilots fall out of the loop. This is the case here. I think combinations of the WX, turbulence, 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 pilots have to agree on what it was and monitor the progress. With 1 pilot 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.

Related reports:

Google
 

Original NASA ASRS Text

Title: 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.

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.