Date: 202002
Local time of day: 0001-0600
Location: ZAU.ARTCC, IL
Aircraft: Regional Jet 700 ER/LR (CRJ700)
Flight plan: IFR
Flight phase: Cruise
Reporter organization: Government
Reporter function: Enroute
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Communication Breakdown; Time Pressure
Anomaly: ATC Issue All Types; Airspace Violation All Types; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Provided Assistance
Contributing factors: Airport; Human Factors; Procedure
Primary problem: Human Factors

Narrative: Mid shift. MSN Approach and Tower close at 1100L/0500Z. I was anticipating approach calling to give me the airspace. I had Aircraft Z on frequency descending for MSN. I noticed MKE Approach had Aircraft X about 5 miles in front of Aircraft Z. I called MKE to have them slow Aircraft X so I could a sequence started. I descended Aircraft Z into MKE airspace about 3 miles before their boundary with mine. MSN called and I took the airspace. They had Aircraft Y on final and the pilot was told to cancel on frequency with Center. In the meantime I vectored Aircraft X on a 360 then a 180 heading to build space between him and Aircraft Z. Aircraft Z was approaching the final approach course and I still hadn't received a cancellation from Aircraft Y. I reached out to Aircraft X to attempt Aircraft Y on company frequency and then I called the OMIC desk. He inadvertently hung up on me the first time. He called back and I passed the information. He asked a question and paused. I wasn't sure if he hung up again or what happened so I became distracted by this and didn't watch Aircraft X close enough. He clipped a portion of MKE approach and RFD Approach without any coordination. Aircraft X did not come near any other aircraft; it just entered the adjoining airspace. Aircraft Y finally called and cancelled and I was able to get Aircraft Z and Aircraft X into MSN. A few minutes later...The MVA just west of the final approach course for Runway 36 at MSN is 036. Aircraft A checked on inbound for MSN direct to PACOV. I had control from FARMM sector and RFD Approach. I'm certain I descended Aircraft A to 036. I turned the aircraft to a 270 heading to build space between JIA and SKW (2 weeks earlier Aircraft A had to go around twice while inbound to MSN and I didn't want it to happen again). I gave Aircraft A direct PACOV and moved my attention to the MSN arrivals I had next in line. When I got back to Aircraft A the aircraft was descending out of 032. The MVA in that area is 031. I asked Aircraft A to verify altitude and assigned altitude; it responded that it was just leveling off at 030. I issued a low altitude alert and climbed it 031. The pilot and myself questioned each other. He thought I issued 030; I thought I issued 036. I have not listened to the tapes so I'm not sure which is correct. There are always MSN arrivals that land right after MSN closes. Traffic has seemed to pick up in the last month or so though. 3 out of the last 4 mids I have had 8-10 aircraft scheduled to arrive at MSN within the same 15 minute span after they closed. MSN is a one-in; one-out airport once they close. I cannot clear another aircraft for approach until the previous has cancelled. This makes for a complex workload. It would also help immensely if MSN Approach stayed open for another 30 minutes. It would provide a much better service to the aircraft.




Synopsis: ZAU Controller reported difficulties with an airport closing and IFR traffic into the airport after the nightly closure.