ARTCC RADAR CTLR ISSUED AN EXPEDITIOUS DSCNT TO AN ACR ACFT THROUGH AN OCCUPIED ALT. PLT WAS SLOW REACTING TO THE DSCNT AND A SUBSEQUENT TURN RESULTING IN LTSS.

Narrative

ACR X WAS ASKED TO DSND FROM FL370 TO FL290; AND TO EXPEDITE THROUGH FL330; TFC MIL Y AT FL350. AFTER 1 MIN; ACFT DEPARTED FL370. I ISSUED A HDG OF 090 DEGS (APPROX 70 DEG TURN). ACFT WAS SLOW TURNING; CAUSING LOSS OF SEPARATION. ACFT WAS ALSO SLOW IN DSCNT RATE (LESS THAN THE REQUIRED 4000 FT IN 3 MINS). ACFT WAS TCASII EQUIPPED AND RPTED ACFT IN SIGHT. THE LACK OF COMPLIANCE WITH BOTH CLRNCS GIVES THE APPEARANCE THAT THE PLT WAS USING TCASII TO SEPARATE HIMSELF RATHER THAN STRICTLY ADHERING TO THE ISSUED CLRNCS. THE ACFT DID NOT ACHIEVE 4000 FT IN 3 MINS DESPITE BEING ASKED TO EXPEDITE. THE ACFT WAS TURNED IN EXCESS OF 70 DEGS; EVEN THOUGH ONLY 15-20 DEGS WERE REQUIRED FOR SEPARATION. THE ACFT DID NOT IN FACT TURN FOR 1 MIN; AND DID NOT ACHIEVE THE 20 DEGS OF TURN THAT WOULD HAVE PROVIDED SEPARATION. ACCORDING TO MY INITIAL CONVERSATION WITH ZAU QUALITY ASSURANCE; THERE IS NO STANDARD FOR TURNS ISSUED TO A PLT. MY QUESTION -- WHEN THE PLT IS GIVEN A TURN; AT WHAT POINT IS IT THE CTLR'S RESPONSIBILITY; AND AT WHAT POINT IS THE ABSENCE OF A REASONABLE TURN THE PLT'S RESPONSIBILITY?