Narrative:

Our aircraft was level at 10000, 250 KTS heading 190 all assigned by mia approach control. TCASII gave 'TA' scope revealed target at 2 O'clock 800 ft low and climbing. Visual scan did not pick up target. 5-10 seconds later TCASII alert 'climb, climb,' autoplt was disconnected power applied and 200-300 FPM climb established while still attempting visual contact. 5 seconds later TCASII alert 'increase climb, increase climb,' 1500 FPM climb established as converging aircraft was visually acquired. We stopped climb at 11300 as approach control issued 'traffic about 2 O'clock less than 1 mi and an small transport Y passed directly beneath our aircraft. I queried approach control as to whether the target had been in radar contact. The reply was affirmative and he gave a telephone number to call on the ground. The outcome of our conversation was that the small transport Y had been erroneously cleared to 10000 ft by departure control. We were pointed out as 'his traffic,' he reported us in sight but I don't believe he took any evasive action.

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Original NASA ASRS Text

Title: POTENTIAL CONFLICT THAT COULD HAVE BEEN A NMAC OR WORSE.

Narrative: OUR ACFT WAS LEVEL AT 10000, 250 KTS HDG 190 ALL ASSIGNED BY MIA APCH CTL. TCASII GAVE 'TA' SCOPE REVEALED TARGET AT 2 O'CLOCK 800 FT LOW AND CLBING. VISUAL SCAN DID NOT PICK UP TARGET. 5-10 SECONDS LATER TCASII ALERT 'CLB, CLB,' AUTOPLT WAS DISCONNECTED PWR APPLIED AND 200-300 FPM CLB ESTABLISHED WHILE STILL ATTEMPTING VISUAL CONTACT. 5 SECONDS LATER TCASII ALERT 'INCREASE CLB, INCREASE CLB,' 1500 FPM CLB ESTABLISHED AS CONVERGING ACFT WAS VISUALLY ACQUIRED. WE STOPPED CLB AT 11300 AS APCH CTL ISSUED 'TFC ABOUT 2 O'CLOCK LESS THAN 1 MI AND AN SMT Y PASSED DIRECTLY BENEATH OUR ACFT. I QUERIED APCH CTL AS TO WHETHER THE TARGET HAD BEEN IN RADAR CONTACT. THE REPLY WAS AFFIRMATIVE AND HE GAVE A TELEPHONE NUMBER TO CALL ON THE GND. THE OUTCOME OF OUR CONVERSATION WAS THAT THE SMT Y HAD BEEN ERRONEOUSLY CLRED TO 10000 FT BY DEP CTL. WE WERE POINTED OUT AS 'HIS TFC,' HE RPTED US IN SIGHT BUT I DON'T BELIEVE HE TOOK ANY EVASIVE ACTION.

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.