Widebody Transport
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (mon) 6
Distraction; Communication Breakdown; Situational Awareness; Time Pressure
ATC Issue All Types; Conflict Airborne Conflict; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Human Factors; Procedure
Aircraft X had departed MSP and was climbing to FL350 north of ALO; passing through FL265. A red alert notified me on my Enroute Decision Support Tool (EDST) that it was a conflict with Aircraft Y. I had handed off Aircraft Y to MSP Center Sector P17 (Mason City). I called P17 and told them COTON (ZAU75) will work Aircraft X at FL310; in order to miss the Aircraft Y at FL330. The P17 controller stated Aircraft X was issued a crossing restriction to top Aircraft Y. The aircraft began to flash when I had noticed Aircraft X was leveling off at FL330. I called P17 and said I am turning Aircraft Y to avoid a traffic alert and loss of separation. He said the aircraft was issued a crossing and could not make it. I said I was going to turn Aircraft Y 25R [25 degrees right]. Mason City turned Aircraft X to a 090 heading. At 6.10 miles I called a traffic alert to Aircraft Y and descended the aircraft to ensure vertical separation. The aircraft lost separation at approximately 300 feet vertically and 4.61 miles laterally. Mason City called me back to say Aircraft X missed his crossing restriction to top Aircraft Y and APREQed direct to IOW after the aircraft was free of conflict from Aircraft Y and positive separation was reestablished. When Mason City takes RADAR or a hand off on an aircraft they need to miss their traffic and not use crossing restrictions for aircraft climbing. This does not seem efficient at all and does not always work.
ZAU Center Controller reported a loss of separation when an aircraft was unable to comply with their issued crossing restriction.