MD88 HAS NMAC ON CLIMB OUT FROM PBI. DEP CTLR FAILED TO NOTE CONFLICT BEFORE TRANSMITTING CLIMB CLRNC.

Narrative

WHILE DEPARTING PBI WE WERE CLRED TO CLB TO FL180 BY PALM BEACH DEP. OUR ALT AT THE TIME OF CLRNC WAS BTWN 7500-8500 FT. AT APPROX 8500 FT MSL; WE RECEIVED A TCAS TA FOR AN ACFT AT OUR 10 O'CLOCK POS; APPROX 6 NM; AND APPROX +1000 FT ABOVE OUR ALT. IT APPEARED TO BE ON A DIRECT CONVERGING COURSE. THE ACFT APPEARED TO BE IN LEVEL FLT GIVEN THE LACK OF TCAS CLB/DSCNT DATA ON THE DISPLAY. I; THE FO; WAS THE PF. THE CAPT WAS PLT MONITORING AND WE HAD A COMPANY PLT ON THE JUMPSEAT. WHILE WE ALL SEARCHED FOR THE ACFT; I IMMEDIATELY REDUCED THE CLB RATE TO 500 FPM. A FEW SECONDS LATER; WE RECEIVED A TCAS RA TO DSND. I DISENGAGED THE AUTOPLT AND LOWERED THE PITCH ATTITUDE TO ACHIEVE THE GREEN BAND ON THE VSI WHICH WAS REQUESTING A DSCNT OF AT LEAST 2000 FPM. WE WERE AT APPROX 9200 FT MSL WHEN THE RA OCCURRED AND DID NOT GET THE CLR OF CONFLICT CALL UNTIL WE HAD DSNDED TO APPROX 8400 FT MSL AT A RATE OF UP TO 3000 FPM. ONCE THE CONFLICT HAD CLRED; WE RPTED THE RA DSCNT TO ATC AND RESUMED OUR PREVIOUS CLRNC TO CLB TO FL180. THE CAPT AND THE JUMPSEATER DID OBTAIN THE ACFT VISUALLY AND ESTIMATED WE HAD COME WITHIN 300 FT. I DID NOT SEE THE ACFT AS I WAS FOCUSED ON CHANGING THE PITCH ATTITUDE TO REMAIN IN THE TCAS COMMANDED GREEN BAND ON THE VSI. AT SOME POINT JUST PRIOR TO THIS EVENT; PALM BEACH DEP HANDED US TO ZMA. THE CLRNC TO CLB TO FL180 WAS ISSUED BY PALM BEACH BEFORE THE TA WAS RECEIVED. ATC GAVE US NO ADVISORY OF THIS TFC BEFORE THE CLB CLRNC OR RADIO HDOF. IN TALKING WITH PALM BEACH ATC REPRESENTATIVES AFTER THE FLT; IT APPEARS THE CTLR SAW THE CONFLICT AFTER ISSUING THE CLB CLRNC AND HDOF TO MIAMI. HE ATTEMPTED TO NOTIFY MIAMI TO INFORM US BUT IT WAS TOO LATE. IT APPEARS THAT THIS EVENT WAS THE RESULT OF AN ATC ERROR IN ISSUING A CLB CLRNC WHEN A TFC CONFLICT WAS EXISTING. I WAS THANKFUL THE TCAS SYS GAVE US THE HEADS UP AND A COLLISION WAS AVOIDED.