Narrative:

Aircraft Y was handed off to me from the low sector climbing to FL230. I climbed aircraft Y to his requested altitude of FL360. I left him on his filed route. I initiated the handoff and subsequently transferred radio communications after receipt of the handoff. I accepted the handoff on aircraft X around the same time. Aircraft X checked in at FL370 deviating right of course. I believe I issued the weather in the vicinity of ZZZ. I noticed that the other sector ha[d] authorized aircraft Y to deviate for ZZZ1 airport. I did not yet apply merging target procedures as the aircraft targets did not appear to be merging even though they were deviating. As soon as I noticed aircraft Y leave FL360 for FL363 I issued the traffic to aircraft X. I was informed by aircraft X that he was already in a left turn do to an RA he had received. After the aircraft passed each other; aircraft X returned to his normal course and continued to deviate. The pilot of aircraft X queried me as to what had happened. I told him a CRJ900 (no numbers given) had exceeded his assigned altitude. The pilot then asked me for aircraft Y numbers. I told him I couldn't give that over the radio. He asked for and was provided a phone number to call the facility. I don't [know] why it happened. Aircraft Y read back his altitude assignment of FL360. I was told he checked in with sector xx climbing to FL360. Either the pilot was responding to a TCAS climb; he just made a mistake and kept climbing on his own or he took someone else's climb. The TCAS climb doesn't make sense though as there was no aircraft below him in his vicinity.

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Original NASA ASRS Text

Title: With twelve o'clock traffic an A320 at FL370; a CRJ900 climbing to FL360 responded to a TCAS RA 'DESCEND' annunciation which changed to 'CLIMB' as the descent began. The A320 responded to the TCAS RA from the climbing CRJ900. The CRJ900 TCAS did not display the A320 until the RA activated.

Narrative: Aircraft Y was handed off to me from the low sector climbing to FL230. I climbed Aircraft Y to his requested altitude of FL360. I left him on his filed route. I initiated the handoff and subsequently transferred radio communications after receipt of the handoff. I accepted the handoff on Aircraft X around the same time. Aircraft X checked in at FL370 deviating right of course. I believe I issued the weather in the vicinity of ZZZ. I noticed that the other sector ha[d] authorized Aircraft Y to deviate for ZZZ1 Airport. I did not yet apply merging target procedures as the aircraft targets did not appear to be merging even though they were deviating. As soon as I noticed Aircraft Y Leave FL360 for FL363 I issued the traffic to Aircraft X. I was informed by Aircraft X that he was already in a left turn do to an RA he had received. After the aircraft passed each other; Aircraft X returned to his normal course and continued to deviate. The pilot of Aircraft X queried me as to what had happened. I told him a CRJ900 (no numbers given) had exceeded his assigned altitude. The pilot then asked me for Aircraft Y numbers. I told him I couldn't give that over the radio. He asked for and was provided a phone number to call the facility. I don't [know] why it happened. Aircraft Y read back his altitude assignment of FL360. I was told he checked in with Sector XX climbing to FL360. Either the pilot was responding to a TCAS climb; he just made a mistake and kept climbing on his own or he took someone else's climb. The TCAS climb doesn't make sense though as there was no aircraft below him in his vicinity.

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.