Widebody Transport
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 1
Situational Awareness; Communication Breakdown; Troubleshooting; Human-Machine Interface
ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
General None Reported / Taken
Aircraft; Human Factors
Aircraft X was southeast bound at FL350; reported passing KANUA at XA:03Z; estimating KYLLE at XA:36Z. Aircraft Y was northeast bound at FL350; estimating SEDAR at XA:15Z. Initially the two aircraft did not probe in conflict with each other. A time update on one or both aircraft made the atop computer show the two aircraft were going to be in conflict approximately 20 minutes prior to them entering the conflict status; and showed them crossing each other with 14 and a half minutes when 15 minutes are required. Due to the evening rush there were no available altitudes for vertical separation to be established. The Controller working Sector 1 and 2; who was currently active control of Aircraft X; issued Aircraft X an offset 10 miles right of course to establish the lateral separation required. At that moment Aircraft X encountered CPDLC problems and the clearance couldn't be delivered through CPDLC. The Controller at Sector 1 and 2 issued the clearance through [Commercial Radio] as usual when an aircraft encounters CPDLC issues. [Commercial Radio] was unable to reach Aircraft X to issue the clearance. By the time [Commercial Radio] got ahold of Aircraft X the aircraft had already passed each other and Aircraft Y was in radar airspace with ZSE.Make a better attempt to move both aircraft instead of just one.
Oakland Oceanic Controller reported two aircraft at the same altitude; attempting to fix the problem but was unable due to communication failures.