Narrative:

On climb out out of mia, TCASII gave a TA (several) followed by an RA advisory of 'reduce climb.' the copilot was flying and we leveled off at 3500 ft and advised mia departure control of our TA/RA advisory. No visual RA symbols were visible on the TCASII CRT or any colored arc displays on either ivsi's. This verbal RA was most confusing due to the absence of the proper visual displays. The TCASII system was set up as per company operating procedures with a 10 NM range and 'above' selected. The RA threat may have been outside the 10 NM range but I doubt it. Mia departure control advised there was no traffic above us within 15 NM when we called the RA and reported we were leveling at 3500 ft. Then, the TCASII started a proper sequence of TA's leading to an RA because of a new conflict due to our level off at 3500 ft while evaluating the first RA. We never visually idented the reason for the initial RA and I believe it probably was a false or spurious advisory. But, we didn't know that or can't ignore the RA due to company and FAA rules. The departure controller was understanding of our situation and advised the second TA/RA sequence was due to arrival traffic level at 3000 ft. We continued our climb with urging from both the controller and the TCASII RA. My confidence in TCASII is partially due to past false RA's but no one can or should ignore any RA's. But, the system is far from perfect due to the vast complexities and the still developing software TCASII programs. Hopefully, both controllers and pilots can continue to work with and develop the TCASII system. One 'save' will be worth all the false TA's/RA's.

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Original NASA ASRS Text

Title: TCASII RA GIVES FALSE WARNING, AUDIBLE ONLY, AND CREATES POTENTIAL CONFLICT WITH ARR TFC.

Narrative: ON CLBOUT OUT OF MIA, TCASII GAVE A TA (SEVERAL) FOLLOWED BY AN RA ADVISORY OF 'REDUCE CLB.' THE COPLT WAS FLYING AND WE LEVELED OFF AT 3500 FT AND ADVISED MIA DEP CTL OF OUR TA/RA ADVISORY. NO VISUAL RA SYMBOLS WERE VISIBLE ON THE TCASII CRT OR ANY COLORED ARC DISPLAYS ON EITHER IVSI'S. THIS VERBAL RA WAS MOST CONFUSING DUE TO THE ABSENCE OF THE PROPER VISUAL DISPLAYS. THE TCASII SYS WAS SET UP AS PER COMPANY OPERATING PROCS WITH A 10 NM RANGE AND 'ABOVE' SELECTED. THE RA THREAT MAY HAVE BEEN OUTSIDE THE 10 NM RANGE BUT I DOUBT IT. MIA DEP CTL ADVISED THERE WAS NO TFC ABOVE US WITHIN 15 NM WHEN WE CALLED THE RA AND RPTED WE WERE LEVELING AT 3500 FT. THEN, THE TCASII STARTED A PROPER SEQUENCE OF TA'S LEADING TO AN RA BECAUSE OF A NEW CONFLICT DUE TO OUR LEVEL OFF AT 3500 FT WHILE EVALUATING THE FIRST RA. WE NEVER VISUALLY IDENTED THE REASON FOR THE INITIAL RA AND I BELIEVE IT PROBABLY WAS A FALSE OR SPURIOUS ADVISORY. BUT, WE DIDN'T KNOW THAT OR CAN'T IGNORE THE RA DUE TO COMPANY AND FAA RULES. THE DEP CTLR WAS UNDERSTANDING OF OUR SIT AND ADVISED THE SECOND TA/RA SEQUENCE WAS DUE TO ARR TFC LEVEL AT 3000 FT. WE CONTINUED OUR CLB WITH URGING FROM BOTH THE CTLR AND THE TCASII RA. MY CONFIDENCE IN TCASII IS PARTIALLY DUE TO PAST FALSE RA'S BUT NO ONE CAN OR SHOULD IGNORE ANY RA'S. BUT, THE SYS IS FAR FROM PERFECT DUE TO THE VAST COMPLEXITIES AND THE STILL DEVELOPING SOFTWARE TCASII PROGRAMS. HOPEFULLY, BOTH CTLRS AND PLTS CAN CONTINUE TO WORK WITH AND DEVELOP THE TCASII SYS. ONE 'SAVE' WILL BE WORTH ALL THE FALSE TA'S/RA'S.

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.