Date: 202108
Local time of day: 0601-1200
Location: ZTL.ARTCC, GA
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZTL
ATC / advisory: Center ZTL
Second aircraft: Commercial Fixed Wing
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Human factors: Communication Breakdown; Situational Awareness
Second reporter function: First Officer; Pilot Not Flying
Anomaly: ATC Issue All Types; Conflict NMAC; Deviation / Discrepancy - Procedural Clearance
Detector: Automation Aircraft TA; Automation Aircraft RA; Person Flight Crew; Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Took Evasive Action
Contributing factors: Procedure; Human Factors
Primary problem: Human Factors

Narrative: While in cruise flight; approximately 40NM south of ATL; we were given clearance by Atlanta Center to climb from our present assigned altitude; FL370 to FL380. Within a few seconds of initiating a climb; we received a TCAS alert for 'Traffic'. I immediately noticed an aircraft (a large amber TCAS image on the ND (Navigational Display)) at our same altitude '00'; opposite direction. I increased the rate of climb by electing CON (Max Continuous Thrust) on the N1 page of the FMC.Literally seconds later; we received an RA to 'CLIMB'. I immediately disconnected the auto-pilot and manually advanced the power to rapidly climb out of the red displayed warning area on my PFD (Primary Flight Display). At approximately FL380; the TCAS system said to 'Level Off'. At this point I was at 38100 ft. Moments later we received the aural 'Clear of conflict'. Still hand flying; I lowered the nose and descended 100 ft. back to our assigned altitude of FL380. We had just come from an area of weather over Florida and more weather was ahead beyond Atlanta.The radar was on; and I was on a 160 NM scale. In a busy area like ATL; I recalled seeing numerous aircraft on TCAS which was normal and gave no reason for concern. After the event; both of us (Us & Company) advised ATC we received an RA. The Company pilot asked ATC 'what happened back there?'. The controller replied in a broken sounding voice something like: 'I climbed them too late…'. Looking forward; I never saw the oncoming aircraft.My FO (First Officer) said the Company jet passed beneath us from the right side at a slight angle. The last TCAS altitude I recall seeing as we passed was '-02'. Perhaps; I expected that ATC would keep us safely separated at cruise altitude. At the end of the day; TCAS prevented a catastrophic event! No suggestion. I would not have responded any differently than I did.


Second narrative: We were flying at FL370 talking to ATL Center approximately 40NM south of ATL VOR at the time of the event. ATL center gave us clearance to climb to FL380. As we got the clearance; we got a TCAS Traffic Advisory. I reached up to zoom in my ND (Navigational Display). I saw the Yellow Square and 00" next to it. During this time; the Captain had set the new altitude; and pushed the ALT intervene button. I said to the captain; 'We are going to get an RA; get ready'. As soon as I said that; we got the RA and instructions to climb. The Captain promptly disconnected the Auto Pilot and pushed the throttles up to comply with the TCAS Climb command. I saw traffic under us under the left wing. AT FL381 we got the TCAS level off command; then a few seconds later Clear of Conflict. We returned to our assigned altitude of FL380. Company later asked ATC what the reason was for getting that TCAS. The ATL controller admitted fault and said they climbed us late. The causal factor was lapse of attention regarding two aircraft nose to nose at same altitude. ATC issued a turn to avoid traffic rather than slow to happen climb instructions. ATC having more awareness in regards to aircraft in their sector that are at the same altitude."


Synopsis: Air Carrier flight crew reported TCAS RA in cruise flight and flight crew took evasive action.