ACR MLG FLC RPT NMAC WITH TWIN ENG LOW WING ACFT ON CONVERGING COURSE. TCASII EVASIVE ACTION CLB INITIATED BY ACR. CTLR SAYS TFC WAS POP-UP. CTLR TRAINING IN PROGRESS DURING INCIDENT.

Narrative

AT 8000 FT ON THE WEST PALM BEACH SURFN 7 ARR (RADIAL 025 DEGS AT 20 DME); WE ENCOUNTERED POP-UP TCASII TFC AT THE 12 O'CLOCK POS; 400 FT BELOW. WE RECEIVED AN IMMEDIATE TA AND ATTEMPTED TO CONTACT APCH TO VERIFY TFC WITH NO SUCCESS. WE SHORTLY THEREAFTER RECEIVED AN RA WITH TCASII COMMANDS FOR AN IMMEDIATE CLB NO LESS THAN 2000 FPM. PWR WAS APPLIED AND CLB INITIATED TO 8400 FT. WITH SUBSEQUENT AVOIDANCE MANEUVER; TCASII ON TARGET ACFT REMAINED 400 FT BELOW OUR ACFT INDICATING TARGET WAS CLBING THROUGH OUR ALT CONVERGING ON COLLISION COURSE. AFTER AVOIDANCE MANEUVER WAS PERFORMED; ACFT WAS IMMEDIATELY FLOWN BACK TO 8000 FT WITH A CALL TO APCH CTL STATING POP-UP TFC AND TCASII RA DEV. APCH CTL VERIFIED POP-UP TFC AND WE INFORMED THEM OF THE NEAR MISS STATING RPTS WOULD FOLLOW. AFTER ARR; I PERSONALLY CALLED WEST PALM BEACH TWR AND SPOKE DIRECTLY WITH THE SUPVR AND HANDLING CTLR. APPARENTLY; STUDENT CTLR TRAINING WAS IN PROGRESS AND THE SUPERVISING CTLR STATED THE STUDENT WAS A LITTLE REMISS IN CALLING OUT THE POP-UP TARGET; BUT WERE AWARE OF THE ACFT 400 FT BELOW OUR FLT PATH 2 1/4 MI AWAY ON A CONVERGING COURSE. FREQ SATURATION WAS QUITE EVIDENT; MULTIPLE CONTACTS BY ANOTHER VFR ACFT WERE MADE TO CONTACT PBI APCH CTL TO NO AVAIL. ACFT WAS VISUALLY ACQUIRED BY FO NOT FLYING AND APPEARED TO BE TAN OR ORANGE COLOR; TWIN ENG; LOW WING.