Date: 201509
Local time of day: 0001-0600
Location: ZID.ARTCC, IN
Light: Night
Aircraft: Large Transport
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb; Descent
Airspace: Class A ZID
ATC / advisory: Center ZID
Second aircraft: Large Transport
Reporter organization: Government
Reporter function: Supervisor / CIC
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Distraction; Situational Awareness
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued New Clearance
Contributing factors: Human Factors; Procedure
Primary problem: Procedure

Narrative: As the Front Line Manager (FLM); I was nearing the end of my shift of a busy night of odd weather routes and multiple coordination with other controllers; Traffic Management Units (TMU); FLMs; and general area management of breaks/training and other activities. The midnight shift had come in and traffic had eased as usual to combine sectors. The night shift controllers had worked steady and hard all evening and were given a much needed break. While the traffic was steady; it was average volume/complexity for the time of evening; and many of the day's routes were expired or expiring. The weather was in adjacent areas and our sectors were operating as they normally would be.I was managing the two midnight employees plugged in while 5-6 others were on break (two of which were within 10 mins of returning; 2 were 'done' for the evening; and the other midnight person was just starting a break). The midnight person working this event had the Aircraft X stopped at FL350 for traffic; Aircraft Y at FL360. He lapsed in judgement; climbed Aircraft X to FL370; then after several seconds cleared Aircraft X to turn left and descend. My first indication of this was his increased level of voice and the rapid order of descent; coupled with an audible 'aww; [curse word!]' at the sector. He had overlooked the traffic. I quick-looked his sector scope and watched the altitudes as the aircraft both responded to their respective RAs from TCAS.I admit that a better use of available resources would have served the situation; perhaps using a D-side or two; or re-opening a sector. After an event like this; the question is always answered this way. In my judgement; the traffic was routine and normal for this evening. The night shift briefed the midnighters well; and I was more relaxed than I had been all afternoon. This was a misjudgment on my part and a let-down of my guard to the apparent reduction of traffic.To do it differently; I would plug one more person in; in one of the sectors (likely the one with more complexity; in this case the other sector which was open and not this one). This would not have changed this outcome; but it might have given another set of eyes and ears to the area where they were needed.




Synopsis: ZID Front Line Manager (FLM) reported of a loss of separation when a controller climbed an aircraft through another aircrafts altitude then turns and descends the same aircraft. Controller realized it and the voice inflection is what brought it to the FLM's attention. FLM debated on what could have been done after the fact of the loss of separation.