LGA LCL CTLR RELEASED A B190 FOR TKOF RWY 31 WHILE A CL65 WAS LNDG RWY 22 ON A THREE QUARTER MI FINAL RESULTING IN AN NMAC AND A LOSS OF SEPARATION.

Narrative

I WAS THE PF. WE WERE CLRED FOR THE LOA-A RWY 22 INTO LGA. AGAIN IT WAS NIGHT VMC. WE WERE #3 FOR LNDG AND WE WERE CLRED TO LAND. WE HAD THE ACFT IN TRAIL AS WELL AS THE RWY IN SIGHT. ABOUT 3/4 MI FROM THE RWY; A NEW CTLR TOOK OVER TWR AND AGAIN CLRED US TO LAND. CTLR DEPARTED AN ACFT FROM RWY 31 AFTER THE ACFT AHEAD OF US LANDED. ONCE THAT ACFT WAS AIRBORNE; CTLR DEPARTED ANOTHER ACFT (BEECH 1900) FROM RWY 31. AT THIS POINT WE WERE 500 FT AGL. THE CAPT AND I DISCUSSED A GAR. I COULD NOT SEE THE BE-1900; BUT HE HAD IT IN SIGHT. AT 200 FT AGL; THE CTLR TOLD US TO GO AROUND. WE INITIATED THE GAR. THE CAPT COULD STILL SEE THE ACFT AND FROM THE TCASII I COULD SEE IT WAS LESS THAN 100 FT BELOW US. A FLASHING LIGHT CAUGHT MY EYE AND AS I LOOKED TO THE R; I SAW THE B-1900 PASS THROUGH OUR ALT. THE CAPT LATER TOLD ME THAT HE SAW THE BE-190 PITCH DOWN AND SOMEWHAT LEVELED OFF AS THEY PASSED UNDER US. THE PUBLISHED MISSED APCH FOR THE LOA-A RWY 22 IS TO MAINTAIN 2700 FT. AT 1200 FT THE TWR CTLR TOLD US TO FLY RWY HDG AND MAINTAIN 1000 FT. THIS WAS RIDICULOUS BECAUSE I HAD TO NOSE THE ACFT OVER TO ABRUPTLY STOP THE CLB. THIS IS NOT THE PUBLISHED MISSED APCH INSTRUCTION AND NOT EVEN A TURBOJET TFC PATTERN ALT. WITH AN OPEN MIKE YOU COULD HEAR SOMEONE IN THE BACKGND TELLING THE TWR CTLR WHAT TO ASSIGN US. CTLR THEN TOLD US TO TURN L HDG 070 DEGS AND CLB TO 3000 FT. WE THEN CONTACTED DEP. THE CONFIGN (LAND RWY 22; DEPART RWY 31) IS ALWAYS PRONE TO CAUSE GAR'S. HOWEVER; THIS CTLR DID NOT HAVE A GOOD CTL OF WHERE THE LNDG ACFT WAS. IF IT WASN'T FOR THE B-1900 ACFT'S SITUATIONAL AWARENESS (DECREASING THEIR CLB RATE) AND MY CAPT HAVING A VISUAL; WE WOULD HAVE HAD A MIDAIR. UNFORTUNATELY; OUR PAX SAW WHAT HAPPENED AND QUESTIONED WHY THERE WAS 'AN ACFT SO CLOSE TO US.' SECONDLY; TO ME THE MOST UPSETTING; THE CTLR APPARENTLY DIDN'T KNOW THE CORRECT MISSED APCH OR GAR PROCS. TO TELL US TO MAINTAIN 1000 FT IS ABSURD. WE EXPECT AT LEAST 1500 FT AGL OR THE MISSED APCH FOR THE APCH (2700 FT). THERE WAS NO COM BTWN US AND THE TWR AFTERWARDS. LOOKING BACK; WE WOULD HAVE BEEN BETTER OFF LNDG.