Narrative:

My first officer and I were flying flight from el paso to dallas ft worth. The first officer was flying the leg and we were established on J-50, eastbound at FL250. At approximately PM13Z, 20-40 NM west of wink VOR, a yellow TA was annunciated by TCASII on the 20-mi range. A quick look at the monitor revealed a target 2000 ft below on J-50 headed wbound. Within moments, a second yellow TA was annunciated, this time, the target being at 1000 ft below. Both my first officer and I watched it closely, only to observe a red RA continuing to climb up at us and indicated 700 ft below. Also, the ivsi indicated a command to climb at a rate of climb of at least 3500 FPM while an audio 'climb, climb' came out of the TCASII system. I instantly commanded my first officer to climb at maximum rate of climb to avoid the target. I instantly called ATC to advise them of the danger. ATC response was that there was no target there at our fl, but that a military MTR was leveled below us at FL240. We reached an altitude of approximately 26000 ft when recovery was initiated and our aircraft was returned to FL250. At this point the target was visibly behind us on TCASII and in the clear. ATC then inquired a few moments later as to our rate of climb. I replied '3500- 4000 FPM.' ATC then indicated an altitude deviation had to be reported. I reaffirmed to ATC that we indeed had a dangerous situation, and that TCASII had both visually and aurally commanded a climb. ATC said the MTR was climbing at a high rate of climb, but never left FL240.

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Original NASA ASRS Text

Title: ALTDEV ALT EXCURSION DURING A TCASII RA.

Narrative: MY FO AND I WERE FLYING FLT FROM EL PASO TO DALLAS FT WORTH. THE FO WAS FLYING THE LEG AND WE WERE ESTABLISHED ON J-50, EBOUND AT FL250. AT APPROX PM13Z, 20-40 NM W OF WINK VOR, A YELLOW TA WAS ANNUNCIATED BY TCASII ON THE 20-MI RANGE. A QUICK LOOK AT THE MONITOR REVEALED A TARGET 2000 FT BELOW ON J-50 HEADED WBOUND. WITHIN MOMENTS, A SECOND YELLOW TA WAS ANNUNCIATED, THIS TIME, THE TARGET BEING AT 1000 FT BELOW. BOTH MY FO AND I WATCHED IT CLOSELY, ONLY TO OBSERVE A RED RA CONTINUING TO CLB UP AT US AND INDICATED 700 FT BELOW. ALSO, THE IVSI INDICATED A COMMAND TO CLB AT A RATE OF CLB OF AT LEAST 3500 FPM WHILE AN AUDIO 'CLB, CLB' CAME OUT OF THE TCASII SYS. I INSTANTLY COMMANDED MY FO TO CLB AT MAX RATE OF CLB TO AVOID THE TARGET. I INSTANTLY CALLED ATC TO ADVISE THEM OF THE DANGER. ATC RESPONSE WAS THAT THERE WAS NO TARGET THERE AT OUR FL, BUT THAT A MIL MTR WAS LEVELED BELOW US AT FL240. WE REACHED AN ALT OF APPROX 26000 FT WHEN RECOVERY WAS INITIATED AND OUR ACFT WAS RETURNED TO FL250. AT THIS POINT THE TARGET WAS VISIBLY BEHIND US ON TCASII AND IN THE CLR. ATC THEN INQUIRED A FEW MOMENTS LATER AS TO OUR RATE OF CLB. I REPLIED '3500- 4000 FPM.' ATC THEN INDICATED AN ALTDEV HAD TO BE RPTED. I REAFFIRMED TO ATC THAT WE INDEED HAD A DANGEROUS SITUATION, AND THAT TCASII HAD BOTH VISUALLY AND AURALLY COMMANDED A CLB. ATC SAID THE MTR WAS CLBING AT A HIGH RATE OF CLB, BUT NEVER LEFT FL240.

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.