Narrative:

While being radar vectored for the visual approach to runway 4R ewr; the aircraft was level at 4000 ft on a heading of 170 degrees as assigned by new york TRACON. The crew noticed a TCAS target approaching from the 1 O'clock position also at 4000 ft and less than 5 NM. I obtained visual contact with the other aircraft and confirmed that it was heading directly for us at our altitude. At approximately the same time; new york TRACON issued a traffic alert and instructed us to 'climb immediately' to 5000 ft. The captain was flying and disengaged the autoplt to comply at about the same time TCAS issued a climb RA. As our aircraft climbed through approximately 4600 ft; I witnessed the other aircraft (medium sized bizjet) make a level turn away from us at a range of less than 1/2 mi. Clear of conflict was announced by TCAS and approach and landing were accomplished uneventfully. ATC's explanation of the event was that the other aircraft 'took a bad vector from another controller.' TCAS worked as advertised but both captain and I were surprised at how close other aircraft approached before the activation of the RA event.

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Original NASA ASRS Text

Title: AN ACR CREW REPORTS RESPONDING TO A TCAS RA ON APCH TO EWR AFTER ANOTHER ACFT FAILED TO RESPOND TO AN ATC VECTOR.

Narrative: WHILE BEING RADAR VECTORED FOR THE VISUAL APCH TO RWY 4R EWR; THE ACFT WAS LEVEL AT 4000 FT ON A HDG OF 170 DEGS AS ASSIGNED BY NEW YORK TRACON. THE CREW NOTICED A TCAS TARGET APCHING FROM THE 1 O'CLOCK POS ALSO AT 4000 FT AND LESS THAN 5 NM. I OBTAINED VISUAL CONTACT WITH THE OTHER ACFT AND CONFIRMED THAT IT WAS HEADING DIRECTLY FOR US AT OUR ALT. AT APPROX THE SAME TIME; NEW YORK TRACON ISSUED A TFC ALERT AND INSTRUCTED US TO 'CLB IMMEDIATELY' TO 5000 FT. THE CAPT WAS FLYING AND DISENGAGED THE AUTOPLT TO COMPLY AT ABOUT THE SAME TIME TCAS ISSUED A CLB RA. AS OUR ACFT CLBED THROUGH APPROX 4600 FT; I WITNESSED THE OTHER ACFT (MEDIUM SIZED BIZJET) MAKE A LEVEL TURN AWAY FROM US AT A RANGE OF LESS THAN 1/2 MI. CLR OF CONFLICT WAS ANNOUNCED BY TCAS AND APCH AND LNDG WERE ACCOMPLISHED UNEVENTFULLY. ATC'S EXPLANATION OF THE EVENT WAS THAT THE OTHER ACFT 'TOOK A BAD VECTOR FROM ANOTHER CTLR.' TCAS WORKED AS ADVERTISED BUT BOTH CAPT AND I WERE SURPRISED AT HOW CLOSE OTHER ACFT APCHED BEFORE THE ACTIVATION OF THE RA EVENT.

Data retrieved from NASA's ASRS site as of May 2009 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.