Narrative:

During cruise at FL270 on TCASII, we received a TA warning followed immediately by an RA saying to climb. The copilot was flying and the traffic was coming at us just right of center 1000 ft low. Just as the first officer visually spotted the aircraft the RA went off even though there was 1000 ft of clearance. We started a climb because we were not positive we saw the right aircraft. We informed atlanta center and climbed 400 ft when TCASII said 'clear of conflict.' the other aircraft also reported receiving an RA. After discussing the situation, the copilot and I agreed that the TA was appropriate but the RA was not. A TCASII event questionnaire was submitted per company policy. It seems TCASII needs to be fine-tuned to make it a more useful device.

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Original NASA ASRS Text

Title: ACR MLG ALTDEV EXCURSION FROM CLRNC ALT IN RESPONSE TO TCASII RA AT CRUISE ALT.

Narrative: DURING CRUISE AT FL270 ON TCASII, WE RECEIVED A TA WARNING FOLLOWED IMMEDIATELY BY AN RA SAYING TO CLB. THE COPLT WAS FLYING AND THE TFC WAS COMING AT US JUST R OF CENTER 1000 FT LOW. JUST AS THE FO VISUALLY SPOTTED THE ACFT THE RA WENT OFF EVEN THOUGH THERE WAS 1000 FT OF CLRNC. WE STARTED A CLB BECAUSE WE WERE NOT POSITIVE WE SAW THE RIGHT ACFT. WE INFORMED ATLANTA CENTER AND CLBED 400 FT WHEN TCASII SAID 'CLR OF CONFLICT.' THE OTHER ACFT ALSO RPTED RECEIVING AN RA. AFTER DISCUSSING THE SITUATION, THE COPLT AND I AGREED THAT THE TA WAS APPROPRIATE BUT THE RA WAS NOT. A TCASII EVENT QUESTIONNAIRE WAS SUBMITTED PER COMPANY POLICY. IT SEEMS TCASII NEEDS TO BE FINE-TUNED TO MAKE IT A MORE USEFUL DEVICE.

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.