Narrative:

The flight was from sua to tmb. We departed sua at PM45Z VFR and picked up an IFR clearance to tmb and was assigned 8000 ft MSL. Upon entering the mia terminal area we were assigned a lower altitude of 6000 ft (if memory serves me). It was possibly 4000 ft MSL. Anyhow, we complied with the clearance. When in the descent or after leveling -- I don't recall -- we received a TCASII alert and I looked out the window and spotted an airliner at about 1-2 O'clock position, nwbound. We were sswbound and the PF and myself were assured that no evasive action was needed, so we continued on the assigned clearance. The remainder of the flight was uneventful and we landed safely at tmb. While taxiing to the ramp, the ground controller said that ZMA wanted to talk with us and I obliged by calling him. It seemed to me that he (the ATC supervisor) was concerned that there had been a loss of sep and wanted my input. I discussed with him that I thought that there had been no problem with the safety of our flight, and that there had been no loss of separation as far as we were concerned. I gathered that the B757 had to level off to be in compliance with his TCASII alert. In retrospect we complied with our clearance and didn't see any problem with the safety of our flight, or the other.

Related reports:

Google
 

Original NASA ASRS Text

Title: A DSNDING BEECH 400 CPR JET PASSES WITHIN 7500 FT HORIZLY AND 1000 FT VERTLY FROM A CLBING B757 IN MIA CLASS B AIRSPACE. THE B757 HAD LEVELED OFF FROM THEIR CLB DUE TO THEIR TCASII RA. MIA TRACON SUPVR CALLS THE BE400 CREW FOR A REVIEW.

Narrative: THE FLT WAS FROM SUA TO TMB. WE DEPARTED SUA AT PM45Z VFR AND PICKED UP AN IFR CLRNC TO TMB AND WAS ASSIGNED 8000 FT MSL. UPON ENTERING THE MIA TERMINAL AREA WE WERE ASSIGNED A LOWER ALT OF 6000 FT (IF MEMORY SERVES ME). IT WAS POSSIBLY 4000 FT MSL. ANYHOW, WE COMPLIED WITH THE CLRNC. WHEN IN THE DSCNT OR AFTER LEVELING -- I DON'T RECALL -- WE RECEIVED A TCASII ALERT AND I LOOKED OUT THE WINDOW AND SPOTTED AN AIRLINER AT ABOUT 1-2 O'CLOCK POS, NWBOUND. WE WERE SSWBOUND AND THE PF AND MYSELF WERE ASSURED THAT NO EVASIVE ACTION WAS NEEDED, SO WE CONTINUED ON THE ASSIGNED CLRNC. THE REMAINDER OF THE FLT WAS UNEVENTFUL AND WE LANDED SAFELY AT TMB. WHILE TAXIING TO THE RAMP, THE GND CTLR SAID THAT ZMA WANTED TO TALK WITH US AND I OBLIGED BY CALLING HIM. IT SEEMED TO ME THAT HE (THE ATC SUPVR) WAS CONCERNED THAT THERE HAD BEEN A LOSS OF SEP AND WANTED MY INPUT. I DISCUSSED WITH HIM THAT I THOUGHT THAT THERE HAD BEEN NO PROB WITH THE SAFETY OF OUR FLT, AND THAT THERE HAD BEEN NO LOSS OF SEPARATION AS FAR AS WE WERE CONCERNED. I GATHERED THAT THE B757 HAD TO LEVEL OFF TO BE IN COMPLIANCE WITH HIS TCASII ALERT. IN RETROSPECT WE COMPLIED WITH OUR CLRNC AND DIDN'T SEE ANY PROB WITH THE SAFETY OF OUR FLT, OR THE OTHER.

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.