Narrative:

While descending on the norwich 2 arrival to bos, center cleared air carrier flight abc 'direct pvd, cross at 11000 ft at 250 KTS.' just overhead the pvd VOR and stabilizing at 250 KTS, the controller issued a clearance to 'turn right heading 110 degrees, descent to 8000 ft, speed 280 KTS, spacing into boston.' I read back the clearance and the first officer (flying at the time) input 10000 ft on the MCP altitude window, heading 110 degrees, and initiated a vertical speed mode descent at approximately 1000 FPM. I clarified 8000 ft assigned when we both pointed at the altitude window and he stated that he heard 10000 ft. At this time the controller was very busy with several aircraft and issuing many clrncs. After a few seconds I had a break in the communications to verify the altitude assigned as 8000 ft. The controller responded with 'you're assigned 11000 ft.' the first officer immediately reset 11000 ft in the window and set a vertical speed climb back to 11000 ft. At this time I was acknowledging the clearance and checking the TCASII display for conflicts (TCASII was in 20 NM scale, set to look 'below'). No traffic was observed within 8-10 NM and no TA or RA symbols or warnings were observed. Another aircraft on the frequency was heard to ask 'who screwed this up, up here?...' as we leveled off at 11000 ft heading 110 degrees the first officer and I commented on the unusual method of speeding up for spacing in boston. Then the controller issued us a frequency change and the voice seemed different, possibly another controller taking over. During the brief descent we went from 11000 ft to 10400 ft and back to 11000 ft. No mention of the situation was made to us by any ATC agency and no lack of separation was observed. Possible contributing factors: busy controller, heading 'same' as altitude, ie, 110 degrees and 11000 ft, multiple aircraft on frequency.

Google
 

Original NASA ASRS Text

Title: MLG CREW HAD ARTCC RADAR CTLR MISSPEAK CLRNC.

Narrative: WHILE DSNDING ON THE NORWICH 2 ARR TO BOS, CTR CLRED ACR FLT ABC 'DIRECT PVD, CROSS AT 11000 FT AT 250 KTS.' JUST OVERHEAD THE PVD VOR AND STABILIZING AT 250 KTS, THE CTLR ISSUED A CLRNC TO 'TURN R HEADING 110 DEGS, DSCNT TO 8000 FT, SPD 280 KTS, SPACING INTO BOSTON.' I READ BACK THE CLRNC AND THE FO (FLYING AT THE TIME) INPUT 10000 FT ON THE MCP ALT WINDOW, HEADING 110 DEGS, AND INITIATED A VERT SPD MODE DSCNT AT APPROX 1000 FPM. I CLARIFIED 8000 FT ASSIGNED WHEN WE BOTH POINTED AT THE ALT WINDOW AND HE STATED THAT HE HEARD 10000 FT. AT THIS TIME THE CTLR WAS VERY BUSY WITH SEVERAL ACFT AND ISSUING MANY CLRNCS. AFTER A FEW SECONDS I HAD A BREAK IN THE COMS TO VERIFY THE ALT ASSIGNED AS 8000 FT. THE CTLR RESPONDED WITH 'YOU'RE ASSIGNED 11000 FT.' THE FO IMMEDIATELY RESET 11000 FT IN THE WINDOW AND SET A VERT SPD CLB BACK TO 11000 FT. AT THIS TIME I WAS ACKNOWLEDGING THE CLRNC AND CHKING THE TCASII DISPLAY FOR CONFLICTS (TCASII WAS IN 20 NM SCALE, SET TO LOOK 'BELOW'). NO TFC WAS OBSERVED WITHIN 8-10 NM AND NO TA OR RA SYMBOLS OR WARNINGS WERE OBSERVED. ANOTHER ACFT ON THE FREQ WAS HEARD TO ASK 'WHO SCREWED THIS UP, UP HERE?...' AS WE LEVELED OFF AT 11000 FT HEADING 110 DEGS THE FO AND I COMMENTED ON THE UNUSUAL METHOD OF SPEEDING UP FOR SPACING IN BOSTON. THEN THE CTLR ISSUED US A FREQ CHANGE AND THE VOICE SEEMED DIFFERENT, POSSIBLY ANOTHER CTLR TAKING OVER. DURING THE BRIEF DSCNT WE WENT FROM 11000 FT TO 10400 FT AND BACK TO 11000 FT. NO MENTION OF THE SIT WAS MADE TO US BY ANY ATC AGENCY AND NO LACK OF SEPARATION WAS OBSERVED. POSSIBLE CONTRIBUTING FACTORS: BUSY CTLR, HEADING 'SAME' AS ALT, IE, 110 DEGS AND 11000 FT, MULTIPLE ACFT ON FREQ.

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.