Date: 202012
Local time of day: 0601-1200
Location: ZAU.ARTCC, IL
Aircraft: Small Transport
Operator: Air Carrier
Operating under: Part 135
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Landing
Airspace: Class C ZZZ2
ATC / advisory: Center ZAU
Reporter organization: Government
Reporter function: Enroute
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Situational Awareness; Human-Machine Interface; Distraction; Confusion; Communication Breakdown
Second reporter function: Enroute
Anomaly: ATC Issue All Types; Conflict Ground Conflict; Critical; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Weather / Turbulence; Ground Event / Encounter Ground Equipment Issue
Detector: Person Other Person
When detected: Taxi
Result: General None Reported / Taken
Contributing factors: Weather; Human Factors; Chart Or Publication; Environment - Non Weather Related
Primary problem: Weather

Narrative: There was some confusion going into work as I was notified at XA:00 pm for my XA:30 shift  and told not to report to work until XD:45 due to Level 3 cleaning that was taking place. When we arrived at work the control floor was empty and ZAU ARTCC resumed operations at XD:55am with no briefings at all. I was working the MID configuration which includes the following sectors (sector numbers removed) along with the following approach controls (ZZZ1/ZZZ2/ZZZ3/ZZZ4/ZZZ5). During my stint which started at XF:00 am and ending at XI:00 am around XX:50 ZULU I spoke with Aircraft X looking for the ILS to Runway X at ZZZ2. I asked the pilot if he had the current weather at the field along with the NOTAMs and the pilot responded with a yes to the weather and that he had read the NOTAMs yesterday. I then read what I thought was all the pertinent NOTAMs to the aircraft. I vectored Aircraft X for the ILS at ZZZ2 and cleared the aircraft in for the approach. I switched the aircraft to advisories and requested a timely cancellation due to a second aircraft being vectored for the same approach. Aircraft X soon cancelled his IFR and reported a down time along with the condition of the runway and that the ramp area was in a much worse condition. I inadvertently missed the snow removal NOTAM and was later on informed by management that Aircraft X had landed on a runway with snow removal equipment on it. Any usage of the active runway should require call to either the facility or on frequency to prevent any confusion on what is going on at the airport. Any and all NOTAMs that directly effect the runways should be better identified. ZZZ2 had over 15 NOTAMs listed at the airfield which all look identical; if the ones like snow removal were BOLD or even a different color it may help the next person avoid the same mistake I made.


Second narrative: I was notified today upon arrival to work that Aircraft X had landed on a runway occupied by snow removal equipment at the time. I was unaware that this had happened. I was working the assist position when the aircraft was cleared for the visual approach. The Radar Controller had issued the weather and read the NOTAMs to the aircraft and neither of us were aware that snow removal was taking place at the airport. The aircraft canceled IFR prior to landing. I was not made aware of the hazardous situation until the following work shift. This is the third report that I have written on this type of event at this airport! Several years ago; I myself had an aircraft execute a missed approach due to snow removal equipment on the same runway. I of course submitted a report detailing the situation and offered recommendations to prevent the situation from occurring again. I received no feedback. I told my Operations Manager; who was aware of the incident; and was dismissed. I then took it to the local safety council who actually looked into it. However; after some time I was informed that the current procedures would remain in effect. No definite reason was given. If a runway is possibly occupied by snow removal equipment; an aircraft should not be cleared for an approach. Having an aircraft switch frequencies to contact the snow removal crew themselves to land obviously has many drawbacks. The snow removal crew should simply notify the control facility prior to entering the runway. ATC could then close the runway until notified that the snow removal crew has exited the runway. This could be done by radio or phone; thus preventing the situations that have previously occurred.


Synopsis: Center Controllers reported an aircraft landed on a closed runway due to snow removal equipment and not being able to identify the correct NOTAM for the runway closure..