MD-88
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 8
Situational Awareness; Time Pressure
ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew FLC complied w / Automation / Advisory
Procedure
Aircraft X and Aircraft Y were on opposite courses and were going to be in close proximity; separated by 500 vertical feet. I called traffic; Aircraft Y reported Aircraft X in sight. Before targets were closer than 5 miles apart; I issued a descent to Aircraft X to increase vertical separation. He said he was initiating a climb in response to an RA. I said to him 'I don't think you want to do that.' Aircraft X did not climb.I could have done a better job to avoid the TCAS event. The fact that TCAS told him to climb in that event was startling to me.
Air Traffic Controller reported that he advised an MD-88 crew to descend to clear opposing traffic. MD-88 crew complied despite receiving a TCAS RA to climb.