Narrative:

Kept high with mtpp control. Requested and received descent to FL200. About FL210, received TCASII alert of traffic 1000 ft below, immediate vicinity. Advisory to level off. Leveled off at FL210 and traffic passed just off left side 1000 ft below. Appeared to be a military aircraft and he had TCASII also. Then, after reporting clear of traffic, requested and received clearance to what sounded like one zero thousand. Controller was being stepped on by numerous other xmissions and a lot of backgnd noise/telephones ringing, etc. First TCASII alert, conflicting traffic was supposed to be at FL190 or FL160 descending/climbing. I could not tell by controller/aircraft xmissions. Next TCASII RA received as descending through FL190. Traffic 12 O'clock position, same altitude, less than 10 mi and closing rapidly. TCASII advisory to descend complied with. Asked controller what altitude he needed us at and he said 'flight level two one zero thousand.' we had previously heard stepped on transmission and only clearly heard 'one zero thousand.' initiated climb back up, but requested (due to close proximity to airport) and received 10000 ft. A busy end to an otherwise normal flight. Supplemental information from acn 611393: then the controller told us to maintain one zero thousand. I started my descent to one zero thousand. The captain asked me 'didn't he say maintain two one zero?' I said, 'no, he said maintain one zero thousand.' we were passing FL190 when we received a second TCASII RA. When we were able to get a word in on the radio with the controller, he reiterated to maintain FL210. After we landed, we figured out the controller said 'maintain two one zero thousand.'

Related reports:

Google
 

Original NASA ASRS Text

Title: AN A300 FLT CREW RPTED 2 TCASII EVENTS WHEN IN MTPP AIRSPACE, ONE OF WHICH WAS THE OTHER ACFT'S FAULT AND ONE WAS THEIR OWN FAULT.

Narrative: KEPT HIGH WITH MTPP CTL. REQUESTED AND RECEIVED DSCNT TO FL200. ABOUT FL210, RECEIVED TCASII ALERT OF TFC 1000 FT BELOW, IMMEDIATE VICINITY. ADVISORY TO LEVEL OFF. LEVELED OFF AT FL210 AND TFC PASSED JUST OFF L SIDE 1000 FT BELOW. APPEARED TO BE A MIL ACFT AND HE HAD TCASII ALSO. THEN, AFTER RPTING CLR OF TFC, REQUESTED AND RECEIVED CLRNC TO WHAT SOUNDED LIKE ONE ZERO THOUSAND. CTLR WAS BEING STEPPED ON BY NUMEROUS OTHER XMISSIONS AND A LOT OF BACKGND NOISE/TELEPHONES RINGING, ETC. FIRST TCASII ALERT, CONFLICTING TFC WAS SUPPOSED TO BE AT FL190 OR FL160 DSNDING/CLBING. I COULD NOT TELL BY CTLR/ACFT XMISSIONS. NEXT TCASII RA RECEIVED AS DSNDING THROUGH FL190. TFC 12 O'CLOCK POS, SAME ALT, LESS THAN 10 MI AND CLOSING RAPIDLY. TCASII ADVISORY TO DSND COMPLIED WITH. ASKED CTLR WHAT ALT HE NEEDED US AT AND HE SAID 'FLT LEVEL TWO ONE ZERO THOUSAND.' WE HAD PREVIOUSLY HEARD STEPPED ON XMISSION AND ONLY CLRLY HEARD 'ONE ZERO THOUSAND.' INITIATED CLB BACK UP, BUT REQUESTED (DUE TO CLOSE PROX TO ARPT) AND RECEIVED 10000 FT. A BUSY END TO AN OTHERWISE NORMAL FLT. SUPPLEMENTAL INFO FROM ACN 611393: THEN THE CTLR TOLD US TO MAINTAIN ONE ZERO THOUSAND. I STARTED MY DSCNT TO ONE ZERO THOUSAND. THE CAPT ASKED ME 'DIDN'T HE SAY MAINTAIN TWO ONE ZERO?' I SAID, 'NO, HE SAID MAINTAIN ONE ZERO THOUSAND.' WE WERE PASSING FL190 WHEN WE RECEIVED A SECOND TCASII RA. WHEN WE WERE ABLE TO GET A WORD IN ON THE RADIO WITH THE CTLR, HE REITERATED TO MAINTAIN FL210. AFTER WE LANDED, WE FIGURED OUT THE CTLR SAID 'MAINTAIN TWO ONE ZERO THOUSAND.'

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.