NMAC.

Narrative

WE WERE BEING VECTORED FOR A DOWNWIND FOR RWY 6 AT ISP AND GIVEN A 210 DEG HDG AT 2500 FT MSL BY NY APCH FOR OUR LNDG SEQUENCE. WE WERE IN VFR CONDITIONS AND RECEIVING ADVISORIES. NY APCH TURNED US OVER TO ISP TWR. TWR ADVISED US WE WOULD BE #2 FOR LNDG FOLLOWING A GULFSTREAM AT OUR 1 O'CLOCK POS. THE FO SIGHTED THE TFC AND WE ADVISED TWR THE TFC WAS IN SIGHT. TWR ADVISED US TO KEEP OUR APCH IN TIGHT BEHIND THE GULFSTREAM AND WE WERE CLRED TO LAND. HE WAS PUTTING US IN FRONT OF AN ARROW ON A PRACTICE ILS APCH TO RWY 6. AS WE TURNED BASE TO RWY 6; I PICKED UP THE TFC ON THE PRACTICE ILS. AS WE TURNED FINAL; I COULD SEE THAT THE GULFSTREAM WASN'T GOING TO BE CLR OF THE RWY; SO I ASK IF WE COULD CIRCLE TO RWY 10. THE TWR CTLR WAS BUSY AND DIDN'T RESPOND TO MY REQUEST RIGHT AWAY. SO I ASKED AGAIN AND HE TOLD US TO CIRCLE TO RWY 10 AND CLRED US TO LAND. THERE WAS A HELI SW OF THE RWYS THAT WAS HEADED TOWARDS THE CTR OF THE ARPT TO LAND IN THE INFIELD GRASS. THE TWR CTLR INSTRUCTED THE HELI PLT TO REMAIN CLR OF RWY 10 AND TO TURN AWAY FROM THE RWY. AS WE TURNED SHORT FINAL; THE HELI CONTINUED TOWARDS US. THE FO; WHO WAS FLYING AT THE TIME WAS FIRST TO SPOT THE HELI WAS CONTINUING TOWARDS US AND TURNED L AWAY FROM THE HELI EXECUTING A MISSED APCH. AS WE STARTED THE MISS; THE TWR CTLR TOLD US TO EXECUTE A MISSED APCH AND FLY RWY HDG. WE CONTINUED AS ON A NORMAL TKOF AND CLB UNTIL DIRECTED BACK FOR ANOTHER LNDG WITHOUT FURTHER INCIDENT. I LATER TALKED WITH THE TWR CTLR AND HE SAID THE PLT GOT CONFUSED AND DIDN'T KNOW WHO THE CTLR WAS TALKING TO. THE HELI HAD PASSED TO OUR R WITHIN A FEW HUNDRED FT.