Narrative:

Air carrier X was involved in a near collision with a piper aerostar. During the descent on a bitho 6 routing to mco. X was given a clearance to cross the lamna intersection at 12000 ft 250 KTS. X was given a TA at 12 O'clock 5 mi at 17000 ft, northbound. No traffic was sighted and the captain suggested that they would take a vector to avoid the conflict. No TCASII traffic was noted. The controller suggested stopping the descent at FL180 till clear of the traffic. X was already descending through FL180 at this time. The aerostar pilot was also given the TA and shortly before passing us reported us in sight. I saw him go by in a slight right bank on our left side approximately 300 ft away. We inquired if the aerostar had a transponder, and were told that he did. We suggested to the controller that the miss was close. The aerostar pilot said that if he had not taken evasive action it was a 'collision course.' continued uneventfully to mco. Follow up action: phone call to ZJX. Spoke to watch supervisor for exchange of information NASA report/captain report/TCASII incident report. Supplemental information from acn 296293: cleared BITH06 arrival to mco to cross lamma intersection at 12000 ft and 250 KTS. Descending through FL240 ft issued a TA of '12 O'clock and 5 mi, 17000 ft.' descending through 18000 ft issued TA of '12 O'clock and 2 mi.' 'maintain 18000 ft.' already at 17500 ft descending we saw the traffic, piper aerostar at 12 O'clock dead ahead course and maneuvering to avoid contact with us. We had a TCASII on board. But at no time did we get an RA. Aerostar pilot reported to ATC that had he not turned away, we would have made contact. Flight continued to destination without incident. Supplemental information from acn 295248: cleared descent to 12000 ft -- passing 18000 ft ATC asked for altitude -- reported passing 18000 ft. ATC requested we level at 18000 ft. TCASII soon showed traffic at approximately 17000 ft in opposite direction. Believe conflict would have occurred had we not leveled at 18000 ft

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Original NASA ASRS Text

Title: ACR X TCASII TA HAD NMAC WITH AEROSTAR. SEE AND AVOID CONCEPT.

Narrative: ACR X WAS INVOLVED IN A NEAR COLLISION WITH A PIPER AEROSTAR. DURING THE DSCNT ON A BITHO 6 RTING TO MCO. X WAS GIVEN A CLRNC TO CROSS THE LAMNA INTXN AT 12000 FT 250 KTS. X WAS GIVEN A TA AT 12 O'CLOCK 5 MI AT 17000 FT, NBOUND. NO TFC WAS SIGHTED AND THE CAPT SUGGESTED THAT THEY WOULD TAKE A VECTOR TO AVOID THE CONFLICT. NO TCASII TFC WAS NOTED. THE CTLR SUGGESTED STOPPING THE DSCNT AT FL180 TILL CLR OF THE TFC. X WAS ALREADY DSNDING THROUGH FL180 AT THIS TIME. THE AEROSTAR PLT WAS ALSO GIVEN THE TA AND SHORTLY BEFORE PASSING US RPTED US IN SIGHT. I SAW HIM GO BY IN A SLIGHT R BANK ON OUR L SIDE APPROX 300 FT AWAY. WE INQUIRED IF THE AEROSTAR HAD A XPONDER, AND WERE TOLD THAT HE DID. WE SUGGESTED TO THE CTLR THAT THE MISS WAS CLOSE. THE AEROSTAR PLT SAID THAT IF HE HAD NOT TAKEN EVASIVE ACTION IT WAS A 'COLLISION COURSE.' CONTINUED UNEVENTFULLY TO MCO. FOLLOW UP ACTION: PHONE CALL TO ZJX. SPOKE TO WATCH SUPVR FOR EXCHANGE OF INFO NASA RPT/CAPT RPT/TCASII INCIDENT RPT. SUPPLEMENTAL INFO FROM ACN 296293: CLRED BITH06 ARR TO MCO TO CROSS LAMMA INTXN AT 12000 FT AND 250 KTS. DSNDING THROUGH FL240 FT ISSUED A TA OF '12 O'CLOCK AND 5 MI, 17000 FT.' DSNDING THROUGH 18000 FT ISSUED TA OF '12 O'CLOCK AND 2 MI.' 'MAINTAIN 18000 FT.' ALREADY AT 17500 FT DSNDING WE SAW THE TFC, PIPER AEROSTAR AT 12 O'CLOCK DEAD AHEAD COURSE AND MANEUVERING TO AVOID CONTACT WITH US. WE HAD A TCASII ON BOARD. BUT AT NO TIME DID WE GET AN RA. AEROSTAR PLT RPTED TO ATC THAT HAD HE NOT TURNED AWAY, WE WOULD HAVE MADE CONTACT. FLT CONTINUED TO DEST WITHOUT INCIDENT. SUPPLEMENTAL INFO FROM ACN 295248: CLRED DSCNT TO 12000 FT -- PASSING 18000 FT ATC ASKED FOR ALT -- RPTED PASSING 18000 FT. ATC REQUESTED WE LEVEL AT 18000 FT. TCASII SOON SHOWED TFC AT APPROX 17000 FT IN OPPOSITE DIRECTION. BELIEVE CONFLICT WOULD HAVE OCCURRED HAD WE NOT LEVELED AT 18000 FT

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.