Date: 201703
Local time of day: 0601-1200
Location: ZAB.ARTCC, NM
Aircraft: Medium Transport
Flight plan: IFR
Flight phase: Cruise
Airspace: Class A ZAB
ATC / advisory: Center ZAB
Reporter organization: Government
Reporter function: Enroute
Reporter qualification: Air Traffic Control Fully Certified
Anomaly: ATC Issue All Types; Airspace Violation All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Separated Traffic
Contributing factors: Airspace Structure; Procedure
Primary problem: Procedure

Narrative: While working R17/68; I was working Aircraft X; doing laser aerial work in CATO EAST. The aircraft was in a block 280B350. When I relieved the controller on position; the relieving controller stated that the Aircraft X 'may' spill out of CATO; and will 'try and tell you' when he is going to spill out. The relieving controller stated that Aircraft X had; in fact; spilled out with him; which necessitated multiple point outs and traffic calls.Approximately 10 minutes after assuming the position; I observed Aircraft X spill out of the southeast corner of CATO East. He flew approximately 3 miles outside of the airspace before turning back. There were not any aircraft in the block stratum so; no potential losses of separation occurred. However; the aircraft made multiple turns right on the northern boundary of CATO east. This created an increased workload because of the high volume of traffic enroute on the airway north of CATO EAST. Not only did I have to closely monitor Aircraft X to take immediate action in the case of a northern spill out; TCAS alerts made numerous aircraft flash conflict multiple times (no loss of separation occurred). The flashing was a distraction and pulled my attention away from a high volume sector.The sector was busy enough that sector 68 was split off. Additionally; the fact that Aircraft X was in a 7000 feet block altitude; means that he conflicted with many more aircraft encompassing that block. It added greatly to the complexity and number of aircraft flashing in conflict.When I notified my supervisor; he said that she had saw an email that the aircraft might spill out of CATO; but had no specific knowledge about it. Apparently; there was some prior discussion about this; but; to my knowledge; it was not disseminated to controllers.Overall; the idea that an aircraft in an ATC Assigned Airspace or other assigned airspace 'may spill out occasionally' is extremely unsafe. It defeats the purposed of a defined restricted airspace if the controller has no idea when or where an aircraft may spill out; and no way to safely protect for it.If the aircraft needs to perform activities that are just outside the confines of CATO East -then the area to be protected needs to be defined better. Rather than use an airspace that doesn't overlay the work area; create a defined set of points that a controller can protect and draw on the radar that the aircraft will not spill out of. It's unsafe to protect CATO EAST if the aircraft will not stay in CATO.Don't split of a sector in the middle of a really high volume session. It was extremely complex and unsafe. I could not give a thorough briefing to the controller opening sector 68.If the aircraft cannot stay within the confines of the designated air space (CATO) then his mission should be suspended/cancelled until a time of less higher volume traffic. Don't allow a block altitude that splits stratums.




Synopsis: ZAB Controller reported about an aircraft that had permission to spill out of a restricted area; and the associated problems.