Narrative:

Over ilmet intersection at FL350; sebound in IMC; saw traffic on TCAS getting closer at our altitude. RA sounded and we descended approximately 1000 ft at about 2000 FPM. Air carrier Y was the other aircraft. They climbed. We were in contact with maiquetia on VHF. I reported over the previous intersection at the fir boundary; and was told to report the fir boundary on the other side. ATC did not tell us of traffic! Told ATC that we responded to an RA and were returning to our altitude. I told ATC that we had just missed another aircraft. He did not seem to understand and told me to report the next intersection. We talked to air carrier Y on 123.45 after the incident. Callback conversation with reporter revealed the following information: the flight crew used standard practice and contacted svzm 10 minutes prior to crossing the fir boundary with their ETA and altitude. This information apparently did not alert the controller that he had two airliners nose to nose at the same altitude. Separation was 400 to 500 feet vertical when the other aircraft passed by.

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Original NASA ASRS Text

Title: B757 FLT CREW REPORTS TCAS RA WHILE SE BOUND ON UL337 NEAR ILMET WITH ANOTHER ACR AT FL350 IN SVZM AIRSPACE. TCAS SUCCESSFULLY SEPARATES THE TWO ACFT.

Narrative: OVER ILMET INTXN AT FL350; SEBOUND IN IMC; SAW TFC ON TCAS GETTING CLOSER AT OUR ALT. RA SOUNDED AND WE DSNDED APPROX 1000 FT AT ABOUT 2000 FPM. ACR Y WAS THE OTHER ACFT. THEY CLBED. WE WERE IN CONTACT WITH MAIQUETIA ON VHF. I RPTED OVER THE PREVIOUS INTXN AT THE FIR BOUNDARY; AND WAS TOLD TO RPT THE FIR BOUNDARY ON THE OTHER SIDE. ATC DID NOT TELL US OF TFC! TOLD ATC THAT WE RESPONDED TO AN RA AND WERE RETURNING TO OUR ALT. I TOLD ATC THAT WE HAD JUST MISSED ANOTHER ACFT. HE DID NOT SEEM TO UNDERSTAND AND TOLD ME TO RPT THE NEXT INTXN. WE TALKED TO ACR Y ON 123.45 AFTER THE INCIDENT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE FLT CREW USED STANDARD PRACTICE AND CONTACTED SVZM 10 MINUTES PRIOR TO CROSSING THE FIR BOUNDARY WITH THEIR ETA AND ALTITUDE. THIS INFORMATION APPARENTLY DID NOT ALERT THE CONTROLLER THAT HE HAD TWO AIRLINERS NOSE TO NOSE AT THE SAME ALTITUDE. SEPARATION WAS 400 TO 500 FEET VERTICAL WHEN THE OTHER ACFT PASSED BY.

Data retrieved from NASA's ASRS site as of January 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.