Narrative:

Location: 35 mi northeast ewr. While being vectored for approach ILS runway 22L ewr at 4000 ft, N90 approach began an animated discussion with bizjet who had not complied with a clearance. At the same time we received a TCASII TA at 12 O'clock position, opposite direction, 5 mi, same altitude. After studying situation for approximately 10 seconds and because ATC frequency was still tied up, first officer (PF) initiated a left turn to avoid an impending conflict. When able we informed ATC who thanked us for the timely turn, stating that it was the correct thing to have done under the circumstances. We were then vectored back in for the approach. Upon arrival ewr, we called TRACON to discuss possible loss of separation. ATC had cpa of 3 mi. We called it 2.5 mi. ATC explained their reduced separation parameters under approach vectoring and with diverging courses. I accepted his explanation and agreed not to file an near midair collision report. This is being submitted as an as soon as possible for record purposes and in order to highlight a communications problem in this environment. We had WX and high density communications. The bizjet had executed a portion of his clearance (a descent to our altitude), but not executed a turn because he was not sure of the turn clearance. While waiting to get back on the frequency and confirm, traffic conflict developed with us. That was the first communication problem. Secondly, we received a TA and not being able to get on the frequency, and not knowing whether bizjet had TCASII, we acted to assure separation by commencing a turn. This was the second instance of either action or non action due to congested frequency. ATC agreed with and appreciated our action. This report documents 2 problems with a congested ATC frequency which nearly resulted in loss of separation.

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Original NASA ASRS Text

Title: A B757-200 FLC ALMOST LOSES SEPARATION FROM AN OPPOSITE DIRECTION BIZJET AT THEIR ALT WHILE IN CTL WITH N90, NY.

Narrative: LOCATION: 35 MI NE EWR. WHILE BEING VECTORED FOR APCH ILS RWY 22L EWR AT 4000 FT, N90 APCH BEGAN AN ANIMATED DISCUSSION WITH BIZJET WHO HAD NOT COMPLIED WITH A CLRNC. AT THE SAME TIME WE RECEIVED A TCASII TA AT 12 O'CLOCK POS, OPPOSITE DIRECTION, 5 MI, SAME ALT. AFTER STUDYING SIT FOR APPROX 10 SECONDS AND BECAUSE ATC FREQ WAS STILL TIED UP, FO (PF) INITIATED A L TURN TO AVOID AN IMPENDING CONFLICT. WHEN ABLE WE INFORMED ATC WHO THANKED US FOR THE TIMELY TURN, STATING THAT IT WAS THE CORRECT THING TO HAVE DONE UNDER THE CIRCUMSTANCES. WE WERE THEN VECTORED BACK IN FOR THE APCH. UPON ARR EWR, WE CALLED TRACON TO DISCUSS POSSIBLE LOSS OF SEPARATION. ATC HAD CPA OF 3 MI. WE CALLED IT 2.5 MI. ATC EXPLAINED THEIR REDUCED SEPARATION PARAMETERS UNDER APCH VECTORING AND WITH DIVERGING COURSES. I ACCEPTED HIS EXPLANATION AND AGREED NOT TO FILE AN NMAC RPT. THIS IS BEING SUBMITTED AS AN ASAP FOR RECORD PURPOSES AND IN ORDER TO HIGHLIGHT A COMS PROB IN THIS ENVIRONMENT. WE HAD WX AND HIGH DENSITY COMS. THE BIZJET HAD EXECUTED A PORTION OF HIS CLRNC (A DSCNT TO OUR ALT), BUT NOT EXECUTED A TURN BECAUSE HE WAS NOT SURE OF THE TURN CLRNC. WHILE WAITING TO GET BACK ON THE FREQ AND CONFIRM, TFC CONFLICT DEVELOPED WITH US. THAT WAS THE FIRST COM PROB. SECONDLY, WE RECEIVED A TA AND NOT BEING ABLE TO GET ON THE FREQ, AND NOT KNOWING WHETHER BIZJET HAD TCASII, WE ACTED TO ASSURE SEPARATION BY COMMENCING A TURN. THIS WAS THE SECOND INSTANCE OF EITHER ACTION OR NON ACTION DUE TO CONGESTED FREQ. ATC AGREED WITH AND APPRECIATED OUR ACTION. THIS RPT DOCUMENTS 2 PROBS WITH A CONGESTED ATC FREQ WHICH NEARLY RESULTED IN LOSS OF SEPARATION.

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.