Narrative:

Center issued a descent to FL190. I read back the clearance and the first officer initiated descent. At about FL250, center requested that we expedite to FL190. I read back the clearance and the first officer increased descent rate to 3000 FPM. Through FL230, center requested that we stop descent at FL200. I read back stop at FL200 and the first officer reset the other air carrier altitude select to FL200. Next ATC transmission was to aircraft Y, telling them to stop climb at FL200 due to traffic. The first officer and I both heard this and agreed we didn't like the situation. I queried ATC about our altitude, asking him to confirm FL200. ATC replied, 'no, you should be stopping at FL210.' we were leveling at FL200 at this time, so I reported to ATC that we were at FL200. He said ok, and gave other air carrier aircraft Y a turn. At this time we got an RA commanding 'monitor vertical speed.' ATC said 'aircraft X descend now to FL190,' which I read back. First officer began a descent. At this time, aircraft Y reported that they were climbing, I assume this was due to an RA. I believe that this situation was created by a miscom from ATC, contributing was a lack of situational awareness by aircraft Y in accepting FL200.

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Original NASA ASRS Text

Title: A CL65 FLC HAS A POTENTIAL CONFLICT WITH ANOTHER ACR FLT WHEN ATC ASSIGNS THE SAME ALT FOR DSNDING CLBING TFC NEAR PHL, PA.

Narrative: CTR ISSUED A DSCNT TO FL190. I READ BACK THE CLRNC AND THE FO INITIATED DSCNT. AT ABOUT FL250, CTR REQUESTED THAT WE EXPEDITE TO FL190. I READ BACK THE CLRNC AND THE FO INCREASED DSCNT RATE TO 3000 FPM. THROUGH FL230, CTR REQUESTED THAT WE STOP DSCNT AT FL200. I READ BACK STOP AT FL200 AND THE FO RESET THE OTHER ACR ALT SELECT TO FL200. NEXT ATC XMISSION WAS TO ACFT Y, TELLING THEM TO STOP CLB AT FL200 DUE TO TFC. THE FO AND I BOTH HEARD THIS AND AGREED WE DIDN'T LIKE THE SIT. I QUERIED ATC ABOUT OUR ALT, ASKING HIM TO CONFIRM FL200. ATC REPLIED, 'NO, YOU SHOULD BE STOPPING AT FL210.' WE WERE LEVELING AT FL200 AT THIS TIME, SO I RPTED TO ATC THAT WE WERE AT FL200. HE SAID OK, AND GAVE OTHER ACR ACFT Y A TURN. AT THIS TIME WE GOT AN RA COMMANDING 'MONITOR VERT SPD.' ATC SAID 'ACFT X DSND NOW TO FL190,' WHICH I READ BACK. FO BEGAN A DSCNT. AT THIS TIME, ACFT Y RPTED THAT THEY WERE CLBING, I ASSUME THIS WAS DUE TO AN RA. I BELIEVE THAT THIS SIT WAS CREATED BY A MISCOM FROM ATC, CONTRIBUTING WAS A LACK OF SITUATIONAL AWARENESS BY ACFT Y IN ACCEPTING FL200.

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.