Date: 202012
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: Wind
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Parked
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown; Workload; Time Pressure; Situational Awareness; Distraction
Second reporter function: Dispatcher
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR
Detector: Person Dispatch; Person Flight Crew
When detected: Aircraft In Service At Gate
Result: General None Reported / Taken
Contributing factors: Environment - Non Weather Related; Human Factors; Staffing; ATC Equipment / Nav Facility / Buildings; Airport
Primary problem: Human Factors

Narrative: Typical peak afternoon departure.  Estimated 1hr late with 2 MELs; one unfamiliar. Flap system inoperative. About 25 minutes after show time finally got notice and it showed aircraft nearly fully loaded with 1 can to go. Went to aircraft and still pushed late.  After engine start got ECAM flaps extended.  Since flaps should have been fixed in the closed position I believed it was a problem.  Maintenance believed it was an expected spurious ECAM due to the MEL.  It took over 40 minutes to taxi to maintenance area; make calls to duty officer; and attempt calls to 2 tech pilots to finally have Maintenance on ground visually confirm that the notch flap on the left wing was not retracted and the ECAM warning was real.  Returned to gate; tail swapped and blocked out in just under 2 hours.  Nice job by everyone involved.  Flight to ZZZ was uneventful until approach control informed us the Tower was closed due to COVID.  We flew a box pattern while simultaneously looking at ZZZ1 as alternate (we could get there with 10;000 pounds of fuel due to Captain added fuel) and FO working ACARS to get non-Tower approval.  We briefed the details and flew an instrument approach in VFR conditions to an uneventful landing and block in at destination airport.  After block in I studied the events and our crew response and believed we did an excellent job under the conditions but noted the newest FOM revision required an alternate to operate to a non-towered airport; which we did not have.  The following morning; further study showed that the normally 24 hour Tower may have been closed due to COVID; but there was indeed a NOTAM for the closure which both I and the Dispatcher missed.The confusing MEL language refers to 'appropriate AFM performance restrictions are applied' led to longer than necessary hunt for those in the AFM when the only restrictions I could find are in the QRH.  The time I spent trying to make sure I didn't miss any restrictions could have been better spent studying the NOTAMs.  The closure NOTAM was found using the iPad app. which sorted the airport closure first; while company's provided NOTAMs sorted the closure near the end next to the airport inop lighting.  The requirement for the alternate seems to be a change in this week's FOM.The missing NOTAM closure is high workload human error sorting through pages of NOTAMs.  Lowering the workload by changing the MEL to point to the restrictions rather than creating a lengthy search would have helped. Company NOTAMs should be sorted more like the iPad app.


Second narrative: Flight was scheduled out and conducted a return to gate. An aircraft swap ensued and then departed. I took the flight over from Dispatcher #1 at shift change. I am unsure if the crew was given any NON-TOWER OPS info before departure. The following NOTAM came into play upon arrival: Air Traffic Control and Air Traffic Control Procedures------------------------------------------------------ZZZ APTZZZ SVC TWR CLOSED CTC CTAF XXY.Z DLYZZZ APTZZZ SVC TWR CLOSED CLASS D SERVICE NOT AVBL CTC ZZZ3ARTCC .4 PRACTICE INSTR APCH NOT AVBL DLYDid not know if the crew or the releasing Dispatcher #1 saw the NOTAM for the Tower closure due to the aircraft swap and delay that occurred.  Which delayed the flight where the NOTAM became an issue.Double check NOTAM closures when flights are delayed for an extended period of time.Checked NOTAMs to verify Tower was closed. ACARSed the crew a non-tower operations worksheet and informed the crew to contact ZZZ Center for arrival procedures.


Synopsis: Air carrier flight crew and Dispatcher reported missing a NOTAM alerting that the destination ATC Tower was closed due to COVID-19.