Narrative:

Flight was cleared for an ILS runway 22 approach (lga) in VMC. At approximately 1800 ft MSL on GS, the tower called helicopter traffic at 1-2 O'clock position at 500 ft MSL crossing right to left, and that the helicopter had us in sight. At approximately 1000 ft MSL, we got a TCASII TA alert followed in 1-2 seconds with a TCASII RA. We did not have a visual with the traffic. The autoplt was disconnected and a TCASII ordered climb (1000-1300 FPM) was initiated. Shortly after establishing our climb, the RA changed to a TA and then simply to a TCASII target. The aircraft was manually flown back to GS and at 500 ft MSL was stabilized, on speed and lined up. The helicopter was never seen but passed 400 ft beneath us with minimal lateral separation (according to TCASII). Lga tower told us that the helicopter had us in sight and that the tower had both the helicopter and us in sight. It was not a comfortable situation. In my opinion, the helicopter should have been told to cross the ILS runway 22 approach course 'between' arriving aircraft 'or' further north of the airport. That would have provided more vertical separation between aircraft and avoid the potential for a TCASII RA.

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Original NASA ASRS Text

Title: B757 ENCOUNTERS HELI TFC SAUNTERING THROUGH THE APCH PATH TO RWY 22 AT LGA AND RESPONDS TO RESULTING TCASII RA BELOW 1000 FT.

Narrative: FLT WAS CLRED FOR AN ILS RWY 22 APCH (LGA) IN VMC. AT APPROX 1800 FT MSL ON GS, THE TWR CALLED HELI TFC AT 1-2 O'CLOCK POS AT 500 FT MSL XING R TO L, AND THAT THE HELI HAD US IN SIGHT. AT APPROX 1000 FT MSL, WE GOT A TCASII TA ALERT FOLLOWED IN 1-2 SECONDS WITH A TCASII RA. WE DID NOT HAVE A VISUAL WITH THE TFC. THE AUTOPLT WAS DISCONNECTED AND A TCASII ORDERED CLB (1000-1300 FPM) WAS INITIATED. SHORTLY AFTER ESTABLISHING OUR CLB, THE RA CHANGED TO A TA AND THEN SIMPLY TO A TCASII TARGET. THE ACFT WAS MANUALLY FLOWN BACK TO GS AND AT 500 FT MSL WAS STABILIZED, ON SPD AND LINED UP. THE HELI WAS NEVER SEEN BUT PASSED 400 FT BENEATH US WITH MINIMAL LATERAL SEPARATION (ACCORDING TO TCASII). LGA TWR TOLD US THAT THE HELI HAD US IN SIGHT AND THAT THE TWR HAD BOTH THE HELI AND US IN SIGHT. IT WAS NOT A COMFORTABLE SIT. IN MY OPINION, THE HELI SHOULD HAVE BEEN TOLD TO CROSS THE ILS RWY 22 APCH COURSE 'BTWN' ARRIVING ACFT 'OR' FURTHER N OF THE ARPT. THAT WOULD HAVE PROVIDED MORE VERT SEPARATION BTWN ACFT AND AVOID THE POTENTIAL FOR A TCASII RA.

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.