ACR MLG ALTDEV IN RESPONSE TO TCASII RA.

Narrative

WE WERE ON THE AQN ARR INTO DFW APCHING CREEK (AQN 040032) LEVEL AT 11000 AND ENGS IDLE SLOWING TO 210 KTS PER THE STAR. SLOWING THROUGH 230 KTS AS THE SLATS WERE COMING OUT WE GOT A TCASII TA FOR 12:30 TFC BELOW US AND CLBING. THE TFC CONTINUED TO CONVERGE. AS THE ENGS SPOOLED UP AND WE STEADIED AT 210 KTS THE TA WENT TO AN RA AND TCASII COMMANDED A 1700 FPM CLB. I WENT TO MAX THRUST AND PULLED THE NOSE UP TO ESTABLISH THE COMMANDED RATE OF CLB. SINCE WE HAD BEEN AT A LOW PWR SETTING THE ENGS WERE SLOW TO RESPOND AND THE PITCH RATE AT 210 KTS WAS LIMITED AS WELL. AT 11300 FT TCASII GAVE 'CLR OF TFC' AND I BROUGHT THE PWR BACK AND EASED THE NOSE OVER. WE TOPPED OUT AT 11500 FT AND ABOUT 240 KTS (ASSIGNED 11000 FT AND 210 KTS) AND RETURNED TO THE STAR ALT AND SPD AS QUICKLY AS I COULD SMOOTHLY DO SO. THE TFC HAD LEVELED OFF AT 10000 (AS IS NORMAL. DEPS GO OUT AT 10000; ARRS IN AT 11000). THE MANEUVER WAS NOT REALLY NECESSARY BUT TCASII HAD NO WAY OF KNOWING HE WAS GOING TO LEVEL OFF SO I CAN'T FAULT THE TCASII LOGIC. ATC HAD NOT CALLED THE TFC AND WE WERE VMC/IMC AND NEVER ACQUIRED THE TFC VISUALLY. ANOTHER CONSIDERATION IS AT THAT SPD AND CONFIGN THE TCASII COMMAND WAS CLOSE TO THE LIMIT OF THE MANEUVER CAPABILITY OF THE ACFT. HAD THIS HAPPENED SOONER; WITH THE ENGS STILL AT IDLE; OR IF WE HAD BEEN LIGHTER AND I HAD DELAYED SLAT EXTENSION; WE WOULD HAVE BEEN VERY CLOSE TO BUFFET.