N90 controller described a loss of separation event when traffic responding to a TCAS RA climbed and...

Narrative:

I was in the process of decombining the arrival positions. It was a clear VFR day and it was a 'target-rich' environment' with many vfrs operating on their own below the class B floor. I had just put aircraft X; a citation arriving hpn from the west; on a vector to the final when I noticed a 1200 code indicating 2;700'. I issued the traffic then momentarily switched my attention eastward to the other arrivals. Shortly thereafter; aircraft X announced he was executing a TCAS RA climb. As I looked back I saw that he was climbing into aircraft Y; a northwest-bound light transport under control of another controller. The pilot initiated a TCAS climb before informing me and separation with aircraft Y was lost immediately. I issued aircraft Y traffic right away but I saw aircraft X's mode C indicate 3;800 before descending again. Recommendation; we have many close calls every day with VFR aircraft operating one or two hundred feet above or below the class B airspace around the ny metro area. Extending the 20-mile ring of the ny class B airspace from the surface to 10;000' MSL would improve safety.

Original NASA ASRS Text

Title: N90 Controller described a loss of separation event when traffic responding to a TCAS RA climbed and conflicted with IFR traffic in another controller's sector; the reporter recommending extensions to the Class B.

Narrative: I was in the process of decombining the arrival positions. It was a clear VFR day and it was a 'target-rich' environment' with many VFRs operating on their own below the Class B floor. I had just put Aircraft X; a Citation arriving HPN from the West; on a vector to the final when I noticed a 1200 code indicating 2;700'. I issued the traffic then momentarily switched my attention Eastward to the other arrivals. Shortly thereafter; Aircraft X announced he was executing a TCAS RA climb. As I looked back I saw that he was climbing into Aircraft Y; a NW-bound Light Transport under control of another controller. The pilot initiated a TCAS climb before informing me and separation with Aircraft Y was lost immediately. I issued Aircraft Y traffic right away but I saw Aircraft X's Mode C indicate 3;800 before descending again. Recommendation; we have many close calls every day with VFR aircraft operating one or two hundred feet above or below the Class B airspace around the NY Metro area. Extending the 20-mile ring of the NY Class B airspace from the surface to 10;000' MSL would improve safety.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	976132
Time
Date	201110
Local Time Of Day	1801-2400
Place
Locale Reference	N90.TRACON
State Reference	NY
Aircraft 1
Make Model Name	Light Transport Low Wing 2 Turbojet Eng
Flight Phase	Cruise Descent
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Approach Departure
Qualification	Air Traffic Control Fully Certified
Person 2
Function	Approach Departure
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict

N90 controller described a loss of separation event when traffic responding to a TCAS RA climbed and conflicted with IFR traffic in another controller's sector; the reporter recommending extensions to the class B.