Narrative:

Was being vectored for ILS approach (runway 19R) by dulles approach, level at 8000 ft MSL. Received clearance 'turn left heading 220 degrees, intercept runway 19R localizer, maintain 5000 ft.' I read back clearance as stated. While descending altitude was 6050 ft, controller called and asked that we state our altitude. I stated 6000 ft for 5000 ft. Controller stated that he told us to maintain 7000 ft. I told him the clearance that I read back previous was to turn left heading 220 degrees, intercept runway 19R localizer, and descend to 5000 ft. He again told me that he said 7000 ft. I stated if we had made a mistake that we apologize. He said that it was ok, there was no conflict, and maintain 5000 ft. No further incident. Our company policy, which we followed, had the PNF handle ATC communication while the PF sets the altitude alerter. The PF then states the altitude and the PNF confirms it by stating the altitude as well as pointing at it. Essentially, it is an effort to eliminate the possibility of setting the wrong altitude in error reading back the clearance to the controller, and both pilots verifying it makes it essentially a triple verification. This triple verification may lead to less than vigilant performance by one or both hearing what they may have wanted to. This is true of the controllers as well. When all inbound arrs from the north arrive over the same intersection, it could lead to repetitive clearance instructions. The controller may usually give altitude clearance to 7000 ft but actually stated 5000 ft and sees something different than was expecting to see on radar. He would most likely feel certain that he stated 7000 ft not 5000 ft. I feel that I could have learned a long lasting lesson if I could have actually sat down with the ATC controller involved and listened to the tape. As a collective, I feel that we could all walk away feeling that working together, this type of incident could be avoided. At this time I don't know who made the mistake. I do, however, know that I am not infallible and the lesson I learned from this is that I must be more vigilant is receiving and adhering to ATC instructions.

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Original NASA ASRS Text

Title: FLC OF A BRITISH JETSTREAM 4100 (BA41) OVERSHOT ATC INTENDED ALT ON DSCNT RESULTING IN ATC INTERVENTION WHEN THEY HAD PASSED ASSIGNED ALT. THE FLC BELIEVE THAT THEY HEARD AND READ BACK A LOWER ALT.

Narrative: WAS BEING VECTORED FOR ILS APCH (RWY 19R) BY DULLES APCH, LEVEL AT 8000 FT MSL. RECEIVED CLRNC 'TURN L HDG 220 DEGS, INTERCEPT RWY 19R LOC, MAINTAIN 5000 FT.' I READ BACK CLRNC AS STATED. WHILE DSNDING ALT WAS 6050 FT, CTLR CALLED AND ASKED THAT WE STATE OUR ALT. I STATED 6000 FT FOR 5000 FT. CTLR STATED THAT HE TOLD US TO MAINTAIN 7000 FT. I TOLD HIM THE CLRNC THAT I READ BACK PREVIOUS WAS TO TURN L HDG 220 DEGS, INTERCEPT RWY 19R LOC, AND DSND TO 5000 FT. HE AGAIN TOLD ME THAT HE SAID 7000 FT. I STATED IF WE HAD MADE A MISTAKE THAT WE APOLOGIZE. HE SAID THAT IT WAS OK, THERE WAS NO CONFLICT, AND MAINTAIN 5000 FT. NO FURTHER INCIDENT. OUR COMPANY POLICY, WHICH WE FOLLOWED, HAD THE PNF HANDLE ATC COM WHILE THE PF SETS THE ALT ALERTER. THE PF THEN STATES THE ALT AND THE PNF CONFIRMS IT BY STATING THE ALT AS WELL AS POINTING AT IT. ESSENTIALLY, IT IS AN EFFORT TO ELIMINATE THE POSSIBILITY OF SETTING THE WRONG ALT IN ERROR READING BACK THE CLRNC TO THE CTLR, AND BOTH PLTS VERIFYING IT MAKES IT ESSENTIALLY A TRIPLE VERIFICATION. THIS TRIPLE VERIFICATION MAY LEAD TO LESS THAN VIGILANT PERFORMANCE BY ONE OR BOTH HEARING WHAT THEY MAY HAVE WANTED TO. THIS IS TRUE OF THE CTLRS AS WELL. WHEN ALL INBOUND ARRS FROM THE N ARRIVE OVER THE SAME INTXN, IT COULD LEAD TO REPETITIVE CLRNC INSTRUCTIONS. THE CTLR MAY USUALLY GIVE ALT CLRNC TO 7000 FT BUT ACTUALLY STATED 5000 FT AND SEES SOMETHING DIFFERENT THAN WAS EXPECTING TO SEE ON RADAR. HE WOULD MOST LIKELY FEEL CERTAIN THAT HE STATED 7000 FT NOT 5000 FT. I FEEL THAT I COULD HAVE LEARNED A LONG LASTING LESSON IF I COULD HAVE ACTUALLY SAT DOWN WITH THE ATC CTLR INVOLVED AND LISTENED TO THE TAPE. AS A COLLECTIVE, I FEEL THAT WE COULD ALL WALK AWAY FEELING THAT WORKING TOGETHER, THIS TYPE OF INCIDENT COULD BE AVOIDED. AT THIS TIME I DON'T KNOW WHO MADE THE MISTAKE. I DO, HOWEVER, KNOW THAT I AM NOT INFALLIBLE AND THE LESSON I LEARNED FROM THIS IS THAT I MUST BE MORE VIGILANT IS RECEIVING AND ADHERING TO ATC INSTRUCTIONS.

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.