Widebody; Low Wing; 4 Turbojet Eng
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 3.5
Training / Qualification; Troubleshooting; Situational Awareness; Distraction; Confusion; Communication Breakdown; Workload
ATC Issue All Types; Airspace Violation All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Separated Traffic
Human Factors; Procedure
During the mid-shift; Seattle Approach had been declared ATC Zero for about an hour due to what turned out to be both controllers on duty being locked out of the control room. During this time; Seattle Center assumed Seattle Approach's airspace. During this period; Seattle Tower called on a landline for a release for Aircraft X aircraft because the dial lines were not working apparently. I or my D-Side issued a release to 9000 for the aircraft on the BANGR departure. I just learned that Seattle Tower actually owns a 10 mile radius up to 5000 MSL around the airport so we did not need to issue the release and I talked to and radar identified the aircraft in their airspace without the proper coordination.I would recommend additional training to Seattle Center and Tower on Seattle Approach contingency procedures and fixing the dial lines (103) between Seattle Center and Seattle Tower.
ZSE Controller describes S46 being ATC Zero. ZSE controllers release aircraft off of SEA and find out later that they did not need to release the aircraft because SEA Tower is responsible for 10 miles around SEA.