A DSNDING B747-200 FLC FAILS TO MAKE THEIR LEVELOFF IN TIME TO PROVIDE THE EXPECTED VERT SEPARATION BTWN THEIR ACFT AND A MIL ACFT ASSIGNED ONE FLT LEVEL ABOVE THEM 30 MI SE OF DEN; CO.

Narrative

B747-200 WAS ISSUED A CLRNC BY ME TO FL190. THE ACFT WAS TURNED L TO A 250 DEG HDG FOR TFC; OTHER TFC AT FL200. AFTER THE B747 LEFT FL200 DSNDING I TURNED THE OTHER ACFT BACK ON COURSE. B747 SIGNIFICANTLY REDUCED ITS DSCNT RATE AND LEVELED AT FL193. 2 1/2 MINS AFTER LEAVING FL200 AND BEING TURNED ON COURSE; AND 1 MIN 10 SECONDS AFTER LEVELING AT FL193; SEPARATION WAS LOST BTWN THE B747 AND OTHER TFC. PRIOR TO THE LOSS OF SEPARATION I VERIFIED THE CLRNC WITH THE B747. I THEN REITERATED THAT IT WAS NOT AT PLT'S DISCRETION. I ADVISED THE PLT OF THE TFC AND ASKED IF HE WAS GOING TO DSND. THE PLT REPLIED THAT THEY WERE LEAVING FL192 AS LATERAL SEPARATION WAS LOST. SUPPLEMENTAL INFO FROM ACN 473658: INITIALLY ON DANDD3 ARR TO DFW. VECTORED TO THE W OFF THE ARR. MULTIPLE DSCNT CLRNCS RECEIVED. CLRED TO DSND TO FL190 AND REJOIN ARR ROUTING AND DANDD WITH NO XING RESTRS. FO'S 'B' AUTOPLT FLYING AND ALT SELECT ARMED FOR FL190. BELOW FL200 AUTOPLT CAPTURED ALT AND GRADUALLY REDUCED DSCNT RATE. ALSO ENG ANTI-ICE WAS SELECTED. #4 ENG INDICATED ANTI-ICE VALVE DID NOT OPEN. PWR WAS ADDED TO OPEN #4 ENG ANTI-ICE VALVE. WHILE DSNDING THROUGH FL193 TCASII ADVISED OF 1 O'CLOCK POS TFC AND COMMANDED LEVEL OR CONTINUE DSCNT. AUTOPLT WAS DISCONNECTED AND ACFT WAS FLOWN MANUALLY TO LEVEL AT FL190.