Date: 201702
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: Snow; 10
Light: Night
Aircraft: Small Transport; Low Wing; 2 Turboprop Eng
Operator: Air Taxi
Operating under: Part 91
Flight plan: IFR
Mission: Ferry / Re-Positioning
Flight phase: Landing
ATC / advisory: CTAF ZZZ
Reporter organization: Air Taxi
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Situational Awareness; Fatigue
Second reporter function: Pilot Flying; First Officer
Anomaly: Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: Other Post-Flight
Result: General None Reported / Taken
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: We took off on a 55 minute; empty reposition leg. Our crew had been on duty for ten hours at the point of departing. This was the third leg. Our incident being reported is landing on a runway that was temporarily closed for snow removal. Earlier in the day weather and NOTAMS were checked. Everything was going to be clear and good weather overall. While enroute the AWOS was checked. ZZZ1 tower was closed. Visibility reported was ten miles; with winds favoring Runway XX. Starting the descent; we were talking to Approach. Cleared for the visual; we continued down while making numerous radio calls with our intentions on CTAF. As it was a clear; full moon night we could easily see everything on the entire field. On final to Runway XX we cancelled our IFR flight plan with Approach. The runway had a few small patches of snow; but nothing noteworthy. After the uneventful landing we taxied to the FBO; closed the plane up and left for the night. The next morning; we got to the FBO and there was a note for us to call the tower. Tower informed us of the NOTAM and closure. We checked our EFB's after realizing this mistake and the old NOTAM started just 20 mins before we took off. While we completely understand the severity of our mistake and understand that this could have been much worse; a couple factors lead to us believing the runway was open. -All runway and glide slope lights were on and glide slope indicated it was working with a planned normal descent -No 'X' on the runway-Approach control didn't mention any NOTAM's; closures; or ask us what runway we were planning-No runway closures mentioned on the AWOS-Runway was plowed and looked like a normal safe-to-land area-We saw snow removal equipment workers on terminal ramps; but not on the runway or adjacent taxiways (they have radios and are supposed to be listening to the CTAF) Since this event we have talked about many ways we can avoid anything like this in the future. We talked about making sure both captain and co-pilot are reviewing the NOTAM's and briefing more thoroughly. We have also become more aware that procedures need to be triple checked at times when fatigue can be a factor; such as the end of a duty period and late night. This incident was preventable and has not been taken lightly by us or our company. Thank you for reviewing this report.


Second narrative: [Report narrative contained no additional information.]


Synopsis: Air taxi flight crew reported they landed on a runway that was closed by NOTAM.