ZHU controller described an inappropriate use of visual separation during a climb through occupied a...

Narrative:

I was working the cll sector which is 8;000 and below. A BE35 was northbound idu-cll at 4;000 ft. This aircraft was NORDO. I had another aircraft go to guard frequency (121.5) and try to raise the aircraft. This was unsuccessful. Aircraft X departed runway 11R southwest bound assigned 3;000 ft. I radar identified aircraft X and issued traffic at 4;000. I also asked him if he was in the clear. He said he was in the clear and subsequently reported the BE35 in sight. I asked if he could maintain visual separation and he said he could. I told aircraft X to maintain visual separation from the bonanza and climbed him to FL230. Aircraft X acknowledged this clearance and started the climb. When aircraft X was through about 3;500 and passed aircraft Y I suddenly realized my error. I did not have to be talking to aircraft Y but I had to have the ability to talk to him. Since he was NORDO I didn't have that ability and therefore according to the rule could not use visual separation. Recommendation; none. I have used visual many times when only talking to one of the aircraft. Nordos are rare. I've never encountered a situation where these elements came together before.

Original NASA ASRS Text

Title: ZHU Controller described an inappropriate use of visual separation during a climb through occupied altitude when one aircraft was NORDO.

Narrative: I was working the Cll Sector which is 8;000 and below. A BE35 was northbound IDU-CLL at 4;000 FT. This aircraft was NORDO. I had another aircraft go to guard frequency (121.5) and try to raise the aircraft. This was unsuccessful. Aircraft X departed Runway 11R southwest bound assigned 3;000 FT. I RADAR identified Aircraft X and issued traffic at 4;000. I also asked him if he was in the clear. He said he was in the clear and subsequently reported the BE35 in sight. I asked if he could maintain visual separation and he said he could. I told Aircraft X to maintain visual separation from the Bonanza and climbed him to FL230. Aircraft X acknowledged this clearance and started the climb. When Aircraft X was through about 3;500 and passed Aircraft Y I suddenly realized my error. I did not have to be talking to Aircraft Y but I had to have the ABILITY to talk to him. Since he was NORDO I didn't have that ability and therefore according to the rule could not use visual separation. Recommendation; none. I have used visual many times when only talking to one of the aircraft. NORDOS are rare. I've never encountered a situation where these elements came together before.

Data retrieved from NASA's ASRS site as of April 2012 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	871432
Time
Date	201001
Local Time Of Day	1201-1800
Place
Locale Reference	ZHU.ARTCC
State Reference	TX
Aircraft 1
Make Model Name	HS 125 Series
Operating Under FAR Part	Part 91
Flight Phase	Initial Climb
Route In Use	None
Flight Plan	IFR
Aircraft 2
Make Model Name	Bonanza 35
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Person 1
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy

ZHU controller described an inappropriate use of visual separation during a climb through occupied altitude when one aircraft was NORDO.