Narrative:

Air carrier X was an overflt at FL260. Air carrier Y was a den departure sebound. X was nwbound. Y was issued a climb clearance to FL270. The conflict alert activated bringing the confliction to my attention. I determined that the best course of action was to continue the climb on Y and descend X to FL240. I descended X to FL240 and told to expedite. I told Y to expedite his climb and fly heading 180 degrees. I received no response. I later realized that Y was executing a TCASII RA and had started a descent. I was not advised of the RA. Now Y and X are both in a descent mode. The TCASII RA was in direct conflict with my intentions to separate the 2 aircraft. I believe, because the TCASII RA was unknown to me, that I was not able to make a correct judgement and decision on how to separate the 2 aircraft. Callback conversation with reporter revealed the following information: reporter stated air carrier X was B757 and air carrier Y was A320. Air carrier Y said he was continuing climb after RA. This was discovered later from tapes. Air carrier X, when issued descent, said he was receiving an RA climb. Reporter said 'I understand.' air carrier X complied with descent clearance, ignoring RA. Regional office told facility to process as an operational error, not TCASII incident.

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Original NASA ASRS Text

Title: ACR Y CLB THROUGH OCCUPIED ALT HAD LTSS FROM ACR X. TCASII LOGIC. TCASII INDUCED LTSS. SYS ERROR.

Narrative: ACR X WAS AN OVERFLT AT FL260. ACR Y WAS A DEN DEP SEBOUND. X WAS NWBOUND. Y WAS ISSUED A CLB CLRNC TO FL270. THE CONFLICT ALERT ACTIVATED BRINGING THE CONFLICTION TO MY ATTN. I DETERMINED THAT THE BEST COURSE OF ACTION WAS TO CONTINUE THE CLB ON Y AND DSND X TO FL240. I DSNDED X TO FL240 AND TOLD TO EXPEDITE. I TOLD Y TO EXPEDITE HIS CLB AND FLY HDG 180 DEGS. I RECEIVED NO RESPONSE. I LATER REALIZED THAT Y WAS EXECUTING A TCASII RA AND HAD STARTED A DSCNT. I WAS NOT ADVISED OF THE RA. NOW Y AND X ARE BOTH IN A DSCNT MODE. THE TCASII RA WAS IN DIRECT CONFLICT WITH MY INTENTIONS TO SEPARATE THE 2 ACFT. I BELIEVE, BECAUSE THE TCASII RA WAS UNKNOWN TO ME, THAT I WAS NOT ABLE TO MAKE A CORRECT JUDGEMENT AND DECISION ON HOW TO SEPARATE THE 2 ACFT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED ACR X WAS B757 AND ACR Y WAS A320. ACR Y SAID HE WAS CONTINUING CLB AFTER RA. THIS WAS DISCOVERED LATER FROM TAPES. ACR X, WHEN ISSUED DSCNT, SAID HE WAS RECEIVING AN RA CLB. RPTR SAID 'I UNDERSTAND.' ACR X COMPLIED WITH DSCNT CLRNC, IGNORING RA. REGIONAL OFFICE TOLD FACILITY TO PROCESS AS AN OPERROR, NOT TCASII INCIDENT.

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.