Date: 202111
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Aircraft: A321
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
ATC / advisory: Ramp ZZZ
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Human factors: Distraction; Workload; Communication Breakdown
Second reporter function: First Officer; Pilot Flying
Anomaly: Deviation / Discrepancy - Procedural Hazardous Material Violation; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: Sometime during later stages of pre-flight; received ACARS message 'NOTOC NOTIFICATION'.  I mentioned this to FO (First Officer); and asked that close out be cross checked for Restricted Article; when received.  Lots of work during pre-flight as ZZZ was using Runway XX w/ a 4-6 kt tailwind.  Data was retrieved; departure briefed thoroughly; and eventually everything was buttoned up and we were ready to go.  After push and engine start; we taxied out; paying attention to winds that Tower was calling out for landing aircraft.  FO briefed closeout; mentioned the R/A (Restricted Article) in forward compartment; and I mentally noted that that was expected.  Takeoff/climb out was uneventful...wasn't until approximately hour and a half later as we were at cruise altitude that it hit me like a thunderbolt...I had never received the actual NOTOC form. Obviously; I was focused in on actual departure procedures; being close to max weight and going with a tailwind.  I think; in back of my mind; the ACARS notification might of had opposite effect it intended...knowing I was going to have an R/A on aircraft; then having that confirmed on closeout; just didn't put my focus on form as it should have...if I had no previous idea of R/A in cargo; but it showed up on closeout; that would have made me stop and give more thought to what was going on.  Next time I get one of those ACARS messages; will do something to remind me not to move until form is in my hand... maybe the old checklist between the throttles trick; or something similar.  Additionally; tunnel vision on a particular concern (heavyweight; tailwind; etc.) can be detrimental as other concerns slip through the cracks. NARRATIVE 2We got an ACARS notification that we'd have a NOTOC. On the load close out we did see the Restricted Article listed in the forward cargo area.   However; about an hour or so into the flight; we realized that we actually never got the NOTOC paperwork.  We had just plain forgotten about it. Probably the main reasons for forgetting about the NOTOC is we were occupied with making sure we were legal for a tailwind takeoff on XXL.  We were busy discussing potential threats; getting tailwind performance; and discussing a flaps 2 APU ON takeoff.  My apologies as this slipped our minds. If we are made aware of a NOTOC; put a reminder in front of us so we will see it before door closure. Usually; the ramp agent hands it to me while accomplishing the walk around; or brings it up to us.  Still; my fault.


Second narrative: We got an ACARS notification that we'd have a NOTOC. On the load close out we did see the Restricted Article listed in the forward cargo area.   However; about an hour or so into the flight; we realized that we actually never got the NOTOC paperwork.  We had just plain forgotten about it. Probably the main reasons for forgetting about the NOTOC is we were occupied with making sure we were legal for a tailwind takeoff on XXL.  We were busy discussing potential threats; getting tailwind performance; and discussing a flaps 2 APU ON takeoff.  My apologies as this slipped our minds. If we are made aware of a NOTOC; put a reminder in front of us so we will see it before door closure. Usually; the ramp agent hands it to me while accomplishing the walk around; or brings it up to us.  Still; my fault.


Synopsis: A321 flight crew reported gate departure without required Hazmat NOTAC on board. Flight crew discovered error 1.5 hours after departure.