FLC; CONFUSED OVER ACFT POS AS RELATED TO DEST ARPT; WANDERS INTO JFK'S ATA AND EXPERIENCES AN ALTDEV IN PLT RESPONSE TO TCASII RA.

Narrative

ON APCH TO LGA AFTER BEING VECTORED AROUND NY AREA; IN AND OUT OF CLOUDS; 3 CHANGES OF ACTIVE RWYS; WE WERE VECTORED ON A DOWNWIND FOR RWY 31. CAPT (PNF) HAD SEEN LGA OFF TO THE R AS WE PASSED IT ON THE N SIDE. A FEW MOMENTS LATER; A VERY HARRIED APCH CTL ASKED IF WE HAD THE RWY IN SIGHT? THE CAPT; FEELING SURE OF HIS POS; ACCEPTED A VISUAL APCH TO RWY 31. UNFORTUNATELY; THE COPLT (PF) DID NOT SEE THE RWY AS CLOUDS WERE NOW OBSCURING THE ARPT AREA. AS WE WERE LOOKING FOR THE RWY; WE BEGAN TO INTRUDE INTO THE JFK ARPT AIRSPACE AT WHICH TIME WE HAD A TCASII RA WARNING; CALLING FOR AN IMMEDIATE CLB; WHICH WE FOLLOWED. AIR TFC/APCH CTLR AT THAT TIME INSTRUCTED US TO TURN N AND DIRECTED US TO LGA RWY 31 THE REST OF THE APCH WAS UNEVENTFUL. THE MORAL OF THIS STORY IS TO NEVER ACCEPT A VISUAL APCH UNLESS YOU KNOW THAT THE PF HAS THE RWY IN SIGHT. THE ATC CTLR SHOULD ALSO GIVE A DIRECTION AND MILEAGE TO THE ARPT; ESPECIALLY IN AN AREA WHERE THERE ARE SEVERAL LARGE ARPTS AND VISIBILITY IS MARGINAL. SUPPLEMENTAL INFO FROM ACN 206267: WE WERE FOLLOWING EXTENDED VECTORS IN A COUNTER CLOCKWISE DIRECTION AROUND THE LGA ARPT AREA. WE APCHED THE NY AREA FROM THE S AND EVENTUALLY MADE 1 COMPLETE CIRCLE AROUND LGA ARPT. THE ACTIVE RWY WAS CHANGED AT LEAST TWICE; AND AT TIMES; WE WERE NOT SURE WHICH RWY OR APCH WAS IN USE. FINALLY; THE CAPT (PNF) DID NOT HAVE THE RWY IN SIGHT AND WAS NOT CONVINCED THAT THE CAPT HAD THE CORRECT RWY IN SIGHT. WE PREMATURELY ACCEPTED A VISUAL APCH WITHOUT ADEQUATE REFS TO COMPLETE THE APCH. SUPPLEMENTAL INFO FROM ACN 206355: CAPT SAID HE HAD ARPT IN SIGHT; SO AND FO DID NOT. DUE TO CROWDED ATC FREQ; WE WERE UNABLE TO GET A NEW HDG BACK TO LGA FOR ALMOST A FULL MIN. WE ALL LEARNED NOT TO SAY 'I HAVE THE ARPT IN SIGHT' UNLESS ALL PLTS HAVE THE ARPT IN SIGHT AND THE WX AND TIME OF DAY IS SUCH THAT LOSING THE ARPT IS NOT A REALISTIC PROBABILITY. ALSO ATC CTLR SHOULD ALWAYS GIVE HDG AND DISTANCE TO THE ARPT WHEN CLRING FOR A VISUAL APCH.