LGT GIVEN CLRNC TO DSND AS TCASII RA SOUNDS.

Narrative

WE WERE ON ATC VECTORS TOWARD TUL FOR RE-RTING TO DFW. SEVERAL HDG VECTORS AND CHANGES WERE MADE BECAUSE OF DFW ARR DELAYS. BOTH ACFT WERE AT 350 DEGS. SIT DEVELOPING UNBEKNOWNST TO ZFW OR FLC OF ACR WAS: ANOTHER ACFT FROM ZKC FLEW INTO ZFW SPACE WITH POSSIBLE NO RADIO CONTACT. SEQUENCE OF EVENTS: ATC ISSUED US A HDG OF 350 DEGS.WITH URGENCY IN THE CTLR'S VOICE; HE THEN ISSUED A HDG OF 030 DEGS. AT THE SAME TIME I OBSERVED A YELLOW TARGET ON THE TCASII SCOPE. NO VOICE. POS APPROX. 1-2 O'CLOCK POS. WITH STRONG URGENCY IN THE CTLR'S VOICE; HE CLRED US TO FL310. AT THE SAME TIME THE TCASII VOICE MODE SAID 'TFC; TFC.' THUS CONFUSING HIS CLRNC TO 310 DEGS. THE COPLT INCREASED HIS BANK RATE TO APPROX 40 DEGS STATING 'SOMETHING IS NOT RIGHT.' AT THE SAME TIME I PULLED THE SPOILER HANDLE FULL AFT AND STATED 'TAKE IT DOWN.' AT APPROX THE SAME TIME THE TCASII VOICE MODE STATED; 'DSND; DSND.' WE DSNDED AT A RATE OF APPROX 6000 FPM UNTIL REACHING FL280. ONLY THEN WAS I ABLE TO CONFIRM THE CLRNC ALT BECAUSE BOTH THE ATC CTLR AND I CONTINUED TO STOP ON EACH OTHERS XMISSIONS. FORTUNATELY; THE SEAT BELT SIGN WAS ON AND ALL PAX WERE IN THEIR SEATS. ALL BUT ONE FLT ATTENDANT WERE SEATED. SHE SAID THAT SHE LEFT THE FLOOR BUT WAS NOT HURT. I HAVE REQUESTED ATC RPT.