ZHU controller reported that he watched two aircraft get close together; not realizing he had one of...

Narrative:

I don't recall the aircraft call signs or the exact time. I was working radar on the poe/aex sector combined. I had track control of aircraft 1; a VFR aircraft. The aircraft was in poe approach airspace; heading northbound; in a very slow climb. Something on the order of 100-200 feet per minute. The aircraft flight plan showed the aircraft was climbing to 11;500. I didn't believe this aircraft would ever hit my airspace; so I handed the data block off to mlu approach. They took the handoff and I 'slant zeroed' the data block.sometime later; I noticed the aircraft on the poe/mlu boundary in conflict alert with aircraft 2; southbound; level at 10;000. I made a mention to my d-side that they were going to be close. Shortly after the two aircraft passed each other; I received a radio call from the pilot of aircraft 1 telling me that an aircraft had just flown past him. Less than 1/8 of a mile. I had no idea that aircraft 1 was on my frequency. I mistakenly believed that poe had switched the aircraft to mlu approach. This was my mistake. The previous controller had; in fact; told me that aircraft 1 was on my frequency. I don't know how I missed this in the briefing. I assume it was because I was looking at other situations on the scope and not listening closely enough to what the previous controller was actually saying.this incident was caused by my own failure to properly listen to the relief briefing. No new recommendations. I simply needed to listen better.

Original NASA ASRS Text

Title: ZHU Controller reported that he watched two aircraft get close together; not realizing he had one of the aircraft on his frequency. Controller reported he did not listen to the relief briefing properly.

Narrative: I don't recall the aircraft call signs or the exact time. I was working radar on the POE/AEX sector combined. I had track control of AIRCRAFT 1; a VFR aircraft. The aircraft was in POE approach airspace; heading northbound; in a very slow climb. Something on the order of 100-200 feet per minute. The aircraft flight plan showed the aircraft was climbing to 11;500. I didn't believe this aircraft would ever hit my airspace; so I handed the data block off to MLU approach. They took the handoff and I 'slant zeroed' the data block.Sometime later; I noticed the aircraft on the POE/MLU boundary in conflict alert with AIRCRAFT 2; southbound; level at 10;000. I made a mention to my D-side that they were going to be close. Shortly after the two aircraft passed each other; I received a radio call from the pilot of AIRCRAFT 1 telling me that an aircraft had just flown past him. Less than 1/8 of a mile. I had no idea that AIRCRAFT 1 was on my frequency. I mistakenly believed that POE had switched the aircraft to MLU approach. This was my mistake. The previous controller had; in fact; told me that AIRCRAFT 1 was on my frequency. I don't know how I missed this in the briefing. I assume it was because I was looking at other situations on the scope and not listening closely enough to what the previous controller was actually saying.This incident was caused by my own failure to properly listen to the relief briefing. No new recommendations. I simply needed to listen better.

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	1373828
Time
Date	201607
Local Time Of Day	1201-1800
Place
Locale Reference	ZHU.ARTCC
State Reference	TX
Aircraft 1
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	Climb
Flight Plan	VFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	Cruise
Flight Plan	IFR
Person 1
Function	Enroute
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 11
Events
Anomaly	Conflict Airborne Conflict Deviation - Procedural Published Material / Policy

ZHU controller reported that he watched two aircraft get close together; not realizing he had one of the aircraft on his frequency. Controller reported he did not listen to the relief briefing properly.