Date: 201704
Local time of day: 1801-2400
Location: D01.TRACON, CO
Weather elements / visibility: Windshear
Aircraft: Medium Transport; Low Wing; 2 Turboprop Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class C D01
ATC / advisory: TRACON D01
Second aircraft: Medium Transport; Low Wing; 2 Turboprop Eng
Reporter organization: Government
Reporter function: Enroute
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Workload; Situational Awareness; Communication Breakdown; Distraction; Confusion; Physiological - Other
Anomaly: ATC Issue All Types; Airspace Violation All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Separated Traffic; Air Traffic Control Issued New Clearance
Contributing factors: Weather; Staffing; Procedure; Human Factors
Primary problem: Weather

Narrative: I was working the R-side at Sector 13; and had fed a few DEN arrivals to Denver Approach when we went into a shutoff situation due to wind shear at DEN airport. I was working the DEN arrivals into a holding stack at WOOKY when I observed an IFR aircraft (Aircraft X) approaching and then entering my airspace without coordination. I brought up the data tag; and called the RAMMS/TOMSN arrival controller at Denver Approach to determine the aircraft's intentions. The controller who answered the line was not aware of the aircraft's intentions. It appeared the aircraft was on a downwind or delay vector. I then approved a point-out on that aircraft. I notified the Controller in Charge (CIC) of the situation. Within the next few minutes; I observed a second IFR aircraft (Aircraft Y) approaching and then entering my airspace without coordination; also apparently on a downwind or delay vector. I called the RAMMS/TOMSN arrival controller to determine the second aircraft's intentions and approve another point-out. Within another few minutes; I observed a third IFR aircraft (Aircraft X; a second time) approaching and entering my airspace without coordination; apparently still on vectors to final or a delay vector. I called the RAMMS/TOMSN arrival controller to approve the third point-out. The CIC observed these events as they occurred; and reported them to ZDV management.I understood that the Denver Approach controllers were experiencing a high workload due to wind shear and the precipitation that was displayed southeast of RAMMS/TOMSN inside Denver Approach's airspace. The uncertain response from the controller who answered the RAMMS/TOMSN line; and the lack of pro-active coordination was apparently due to lack of controller staffing/lack of assistance provided to the controller working the position; such as from a coordinator or assist controller. In the event of a DEN arrival shutoff by Denver Approach; which suggests a high workload; it would seem to make sense that arrival controllers be supported by a coordinator or assist controller.




Synopsis: Denver Center Controller reported uncoordinated airspace violations due to windshear and high workload into DEN Airport.