Narrative:

We were at 4000 ft en route to jfk from syr. It was a clear afternoon with a fair amount of GA aircraft in the vicinity. ATC was fairly busy also and congestion on the frequency was a problem. We noted 2 aircraft on our vicinity on the TCASII and actually foresaw the scenario just prior to it occurring. An aircraft was on a converging course but at 4500 ft. TCASII commanded a descent. I disengaged autoplt and commenced descent. Approximately 10-15 seconds after action, I was at 3600 ft or 3500 ft when we started converging on 2ND aircraft which was at 3500 ft. TCASII now commanded a climb. At this time we acquired the 2ND aircraft, an small aircraft, visually and I started an evasive turn to the right. Controller then queried us in a somewhat alarmed tone of voice as to what we were doing. I briefly explained the situation. The controller seemed satisfied but requested me to send in a 'TCASII form' and also requested that we let him know. We would have been happy to inform him were it not for congestion on frequency. We feel we followed the best course of action. Our training program insists we comply with TCASII commands without question. I feel the TCASII operated properly, but we were caught in the slot between 2 aircraft who, even though not being at our altitude, were close enough to trigger corrective action from TCASII.

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Original NASA ASRS Text

Title: AN LTT CREW RESPONDED TO A TCASII COMMAND TO DSND. THIS PUT THEM IN CONFLICT WITH ANOTHER ACFT REQUIRING AN EVASIVE TURN. THERE WERE LOTS OF 'INDIANS' ABOUT.

Narrative: WE WERE AT 4000 FT ENRTE TO JFK FROM SYR. IT WAS A CLR AFTERNOON WITH A FAIR AMOUNT OF GA ACFT IN THE VICINITY. ATC WAS FAIRLY BUSY ALSO AND CONGESTION ON THE FREQ WAS A PROBLEM. WE NOTED 2 ACFT ON OUR VICINITY ON THE TCASII AND ACTUALLY FORESAW THE SCENARIO JUST PRIOR TO IT OCCURRING. AN ACFT WAS ON A CONVERGING COURSE BUT AT 4500 FT. TCASII COMMANDED A DSCNT. I DISENGAGED AUTOPLT AND COMMENCED DSCNT. APPROX 10-15 SECONDS AFTER ACTION, I WAS AT 3600 FT OR 3500 FT WHEN WE STARTED CONVERGING ON 2ND ACFT WHICH WAS AT 3500 FT. TCASII NOW COMMANDED A CLB. AT THIS TIME WE ACQUIRED THE 2ND ACFT, AN SMA, VISUALLY AND I STARTED AN EVASIVE TURN TO THE R. CTLR THEN QUERIED US IN A SOMEWHAT ALARMED TONE OF VOICE AS TO WHAT WE WERE DOING. I BRIEFLY EXPLAINED THE SITUATION. THE CTLR SEEMED SATISFIED BUT REQUESTED ME TO SEND IN A 'TCASII FORM' AND ALSO REQUESTED THAT WE LET HIM KNOW. WE WOULD HAVE BEEN HAPPY TO INFORM HIM WERE IT NOT FOR CONGESTION ON FREQ. WE FEEL WE FOLLOWED THE BEST COURSE OF ACTION. OUR TRAINING PROGRAM INSISTS WE COMPLY WITH TCASII COMMANDS WITHOUT QUESTION. I FEEL THE TCASII OPERATED PROPERLY, BUT WE WERE CAUGHT IN THE SLOT BTWN 2 ACFT WHO, EVEN THOUGH NOT BEING AT OUR ALT, WERE CLOSE ENOUGH TO TRIGGER CORRECTIVE ACTION FROM TCASII.

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.