Air taxi flight crew reported landing at an airport and being advised that the runway was closed.

Narrative:

I was on an IFR flight to ZZZ to pick up passengers for a part 135 flight. I received vectors to ZZZ and approach control asked what approach I would like at ZZZ. I requested a visual to runway xl at ZZZ. I reported the airport in sight and canceled IFR. I do not recall whether or not we were cleared for the visual approach to xl or not. Change to advisory frequency was approved. (ZZZ tower does not open for another 20 minutes). I switched to the CTAF frequency and announced left base to runway xl. There were no other aircraft in the pattern. Shortly after my radio transmission I heard a very muffled and unreadable transmission only being able to make out [number sequence] 'xyza.' a few minutes later I announced turning final to runway xl. A moment later the same unreadable transmission was received again only able to make out [number sequence] 'xyza'. I thought this was someone on the wrong advisory frequency of xyz.a. We landed uneventful on runway xl and taxied to the FBO. After I shutdown and was exiting the aircraft; an airport authority truck pulled up.person X wearing a covid-19 face mask began yelling at me. Person X stated that 'runway xl is closed and I told you twice' 'runway xl is closed use runway yy or zz'i apologized and told person X that there was no NOTAM for xl being closed and approach said nothing about it; nor did the AWOS.person X again repeated herself saying 'I told you twice that xl was closed. I said we heard two transmissions and that I only heard xyza both times. After the incident I reexamined the notams for ZZZ and there were none mentioning runway xl. ATC did not mention it. The AWOS did not mention it. The af/D does state that when the tower is closed; runway xl is available with ppr.contributing factors to this incident: person X with airport authority trying to give instructions on a hand held radio while wearing a very heavy covid-19 mask making transmission unreadable. Had this transmission been received; a slight turn to final to runway yy would have been made. Better review of the af/D or getting the ppr.

Original NASA ASRS Text

Title: Air taxi flight crew reported landing at an airport and being advised that the runway was closed.

Narrative: I was on an IFR flight to ZZZ to pick up passengers for a Part 135 flight. I received vectors to ZZZ and Approach Control asked what approach I would like at ZZZ. I requested a visual to Runway XL at ZZZ. I reported the airport in sight and canceled IFR. I do not recall whether or not we were cleared for the visual approach to XL or not. Change to advisory frequency was approved. (ZZZ Tower does not open for another 20 minutes). I switched to the CTAF frequency and announced left base to Runway XL. There were no other aircraft in the pattern. Shortly after my radio transmission I heard a very muffled and unreadable transmission only being able to make out [Number sequence] 'XYZA.' A few minutes later I announced turning final to Runway XL. A moment later the same unreadable transmission was received again only able to make out [number sequence] 'XYZA'. I thought this was someone on the wrong advisory frequency of XYZ.A. We landed uneventful on Runway XL and taxied to the FBO. After I shutdown and was exiting the aircraft; an Airport Authority truck pulled up.Person X wearing a COVID-19 face mask began yelling at me. Person X stated that 'Runway XL is closed and I told you twice' 'Runway XL is closed use Runway YY or ZZ'I apologized and told Person X that there was no NOTAM for XL being closed and approach said nothing about it; nor did the AWOS.Person X again repeated herself saying 'I told you twice that XL was closed. I said we heard two transmissions and that I only heard XYZA both times. After the incident I reexamined the NOTAMs for ZZZ and there were none mentioning Runway XL. ATC did not mention it. The AWOS did not mention it. The AF/D does state that when the Tower is closed; Runway XL is Available with PPR.Contributing factors to this incident: Person X with Airport Authority trying to give instructions on a hand held radio while wearing a very heavy COVID-19 Mask making transmission unreadable. Had this transmission been received; a slight turn to final to Runway YY would have been made. Better review of the AF/D or getting the PPR.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1749024
Time
Date	202007
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.TRACON
State Reference	US
Environment
Flight Conditions	VMC
Light	Dawn
Aircraft 1
Make Model Name	Small Transport Low Wing 2 Turboprop Eng
Operating Under FAR Part	Part 135
Flight Phase	Landing
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Captain Pilot Flying
Qualification	Air Traffic Control Fully Certified Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Multiengine
Experience	Air Traffic Control Non Radar 2 Air Traffic Control Radar 5 Flight Crew Last 90 Days 75 Flight Crew Total 6500 Flight Crew Type 700
Person 2
Function	Pilot Flying First Officer
Qualification	Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument
Events
Anomaly	ATC Issue All Types Deviation - Procedural Clearance Ground Incursion Runway