Narrative:

The B190 was on a 310 degree heading south of the localizer when issued approach clearance with a right turn heading 040 degrees and cleared for the ILS 6 approach. The PA31 was on a south or 170 degree heading to be spaced just behind the B190. The B190 either turned slower than expected or the wind, believed to be from the southwest, blew the B190 north of the localizer. The PA31 was turned right to 210 degrees to try to avoid loss of separation, but this was too late. I should have kept the second aircraft wider to guarantee the separation, or used some vertical separation until established on final. This does bring up the point that one of the difficulties as a controller is trying to predict how fast the pilot will respond to the clearance, how sharp they will turn the airplane, and what the wind direction and speed is 2000 ft AGL.

Related reports:

Google
 

Original NASA ASRS Text

Title: N90 CTLR DOES NOT ALLOW FOR WX FACTORS AND IS UNABLE TO STOP CONFLICT BTWN B190 AND PA31 BEING TURNED ONTO JFK ILS RWY 6.

Narrative: THE B190 WAS ON A 310 DEG HDG S OF THE LOC WHEN ISSUED APCH CLRNC WITH A R TURN HDG 040 DEGS AND CLRED FOR THE ILS 6 APCH. THE PA31 WAS ON A S OR 170 DEG HDG TO BE SPACED JUST BEHIND THE B190. THE B190 EITHER TURNED SLOWER THAN EXPECTED OR THE WIND, BELIEVED TO BE FROM THE SW, BLEW THE B190 N OF THE LOC. THE PA31 WAS TURNED R TO 210 DEGS TO TRY TO AVOID LOSS OF SEPARATION, BUT THIS WAS TOO LATE. I SHOULD HAVE KEPT THE SECOND ACFT WIDER TO GUARANTEE THE SEPARATION, OR USED SOME VERT SEPARATION UNTIL ESTABLISHED ON FINAL. THIS DOES BRING UP THE POINT THAT ONE OF THE DIFFICULTIES AS A CTLR IS TRYING TO PREDICT HOW FAST THE PLT WILL RESPOND TO THE CLRNC, HOW SHARP THEY WILL TURN THE AIRPLANE, AND WHAT THE WIND DIRECTION AND SPD IS 2000 FT AGL.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.