Narrative:

Approach control advised us we had traffic at 2-3 O'clock for approximately 3 mi at 4500 ft. Our altitude was 5000 ft and our position was approximately ewr 230/25. WX was clear plus 15. As we continued our vectors for approach, with traffic in sight, it became apparent we were on converging courses with previously called traffic. The captain had asked me to keep an eye on the traffic. The aircraft was supposedly at 4500 ft our TCASII indicated only a 300 ft altitude separation. As our courses continued to converge (less than a mile now) it became apparent that we needed to change our course or altitude to avoid a conflict. My visual indications agreed with TCASII. Altitude separation appeared less than 300 ft and range separation less than 1 mi. I ask ATC to confirm local altimeter. As our courses continued to converge, I told the captain we needed to turn approximately 40 degrees left to get away from the traffic (the traffic was not in sight from his side of our plane). As we started our turn TCASII issued a 'traffic, traffic' call. We advised approach control of our turn on a very congested radio frequency. Simultaneously, TCASII issues a 'climb, climb' call. We did not climb because the traffic was in sight. The traffic called, stated he had us in sight also. 10 seconds after our turn, TCASII returned to normal. No altitude deviations were made, only a heading change to avoid the conflict. The problem could have been avoided if the approach controller was not talking to so many other aircraft. (Too many aircraft on same frequency.) also, if the 1000 ft standard altitude separation had been used.

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Original NASA ASRS Text

Title: MLG TURNS TO EVADE A COMMUTER ON A CONVERGING COURSE. TA GIVEN BY APCH CTLR.

Narrative: APCH CTL ADVISED US WE HAD TFC AT 2-3 O'CLOCK FOR APPROX 3 MI AT 4500 FT. OUR ALT WAS 5000 FT AND OUR POS WAS APPROX EWR 230/25. WX WAS CLR PLUS 15. AS WE CONTINUED OUR VECTORS FOR APCH, WITH TFC IN SIGHT, IT BECAME APPARENT WE WERE ON CONVERGING COURSES WITH PREVIOUSLY CALLED TFC. THE CAPT HAD ASKED ME TO KEEP AN EYE ON THE TFC. THE ACFT WAS SUPPOSEDLY AT 4500 FT OUR TCASII INDICATED ONLY A 300 FT ALT SEPARATION. AS OUR COURSES CONTINUED TO CONVERGE (LESS THAN A MILE NOW) IT BECAME APPARENT THAT WE NEEDED TO CHANGE OUR COURSE OR ALT TO AVOID A CONFLICT. MY VISUAL INDICATIONS AGREED WITH TCASII. ALT SEPARATION APPEARED LESS THAN 300 FT AND RANGE SEPARATION LESS THAN 1 MI. I ASK ATC TO CONFIRM LCL ALTIMETER. AS OUR COURSES CONTINUED TO CONVERGE, I TOLD THE CAPT WE NEEDED TO TURN APPROX 40 DEGS L TO GET AWAY FROM THE TFC (THE TFC WAS NOT IN SIGHT FROM HIS SIDE OF OUR PLANE). AS WE STARTED OUR TURN TCASII ISSUED A 'TFC, TFC' CALL. WE ADVISED APCH CTL OF OUR TURN ON A VERY CONGESTED RADIO FREQ. SIMULTANEOUSLY, TCASII ISSUES A 'CLB, CLB' CALL. WE DID NOT CLB BECAUSE THE TFC WAS IN SIGHT. THE TFC CALLED, STATED HE HAD US IN SIGHT ALSO. 10 SECONDS AFTER OUR TURN, TCASII RETURNED TO NORMAL. NO ALT DEVS WERE MADE, ONLY A HDG CHANGE TO AVOID THE CONFLICT. THE PROB COULD HAVE BEEN AVOIDED IF THE APCH CTLR WAS NOT TALKING TO SO MANY OTHER ACFT. (TOO MANY ACFT ON SAME FREQ.) ALSO, IF THE 1000 FT STANDARD ALT SEPARATION HAD BEEN USED.

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.