Narrative:

We had just switched from phl TRACON to ZNY, level 10000 ft. Center called out VFR traffic at 10500 ft, 1 O'clock, and 5 mi. TCASII was on the 10 mi scale. There were 2 targets on the TCASII both at 1 O'clock, the first 500 ft above us and 5 mi, the second 1000 ft above us and 8 mi. I thought I had a visual on the VFR, 10500 ft traffic. I was wrong. I had visual on the traffic 1000 ft above us. The WX was clear and excellent visibility. I believe it was less than 2 mins after center called out the 10500 ft traffic we got a TCASII RA to descend. Captain immediately followed RA. I advised center we were descending with an RA and asked for vectors away from traffic. At 9600 ft RA stopped and advised clear of conflict and we returned to 10000 ft. I was surprised I never saw the traffic. Center did not call out the other 1 O'clock traffic 1000 ft above us. That was the first target I saw, made the mistake of thinking I had the closer 10500 ft traffic and fixated on it. When we got the RA I again fixated on the ivsi to make sure the captain was following the RA. I did notice during the RA the traffic on TCASII passing, I believe, 600 ft above and estimate a 1/4 mi from us. The captain said he saw the traffic come from the center windshield post going right to left. He thought the traffic was much closer and 300 ft above us. It was my first RA and TCASII did a good job, glad it is required equipment and aboard! I cannot believe the FAA does not require TCASII on all commuter/regional airline equipment.

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Original NASA ASRS Text

Title: ALTDEV ALT EXCURSION DUE TO TCASII RA.

Narrative: WE HAD JUST SWITCHED FROM PHL TRACON TO ZNY, LEVEL 10000 FT. CTR CALLED OUT VFR TFC AT 10500 FT, 1 O'CLOCK, AND 5 MI. TCASII WAS ON THE 10 MI SCALE. THERE WERE 2 TARGETS ON THE TCASII BOTH AT 1 O'CLOCK, THE FIRST 500 FT ABOVE US AND 5 MI, THE SECOND 1000 FT ABOVE US AND 8 MI. I THOUGHT I HAD A VISUAL ON THE VFR, 10500 FT TFC. I WAS WRONG. I HAD VISUAL ON THE TFC 1000 FT ABOVE US. THE WX WAS CLR AND EXCELLENT VISIBILITY. I BELIEVE IT WAS LESS THAN 2 MINS AFTER CTR CALLED OUT THE 10500 FT TFC WE GOT A TCASII RA TO DSND. CAPT IMMEDIATELY FOLLOWED RA. I ADVISED CTR WE WERE DSNDING WITH AN RA AND ASKED FOR VECTORS AWAY FROM TFC. AT 9600 FT RA STOPPED AND ADVISED CLR OF CONFLICT AND WE RETURNED TO 10000 FT. I WAS SURPRISED I NEVER SAW THE TFC. CTR DID NOT CALL OUT THE OTHER 1 O'CLOCK TFC 1000 FT ABOVE US. THAT WAS THE FIRST TARGET I SAW, MADE THE MISTAKE OF THINKING I HAD THE CLOSER 10500 FT TFC AND FIXATED ON IT. WHEN WE GOT THE RA I AGAIN FIXATED ON THE IVSI TO MAKE SURE THE CAPT WAS FOLLOWING THE RA. I DID NOTICE DURING THE RA THE TFC ON TCASII PASSING, I BELIEVE, 600 FT ABOVE AND ESTIMATE A 1/4 MI FROM US. THE CAPT SAID HE SAW THE TFC COME FROM THE CTR WINDSHIELD POST GOING R TO L. HE THOUGHT THE TFC WAS MUCH CLOSER AND 300 FT ABOVE US. IT WAS MY FIRST RA AND TCASII DID A GOOD JOB, GLAD IT IS REQUIRED EQUIP AND ABOARD! I CANNOT BELIEVE THE FAA DOES NOT REQUIRE TCASII ON ALL COMMUTER/REGIONAL AIRLINE EQUIP.

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.