ZFW controller described conflict at 11000 between IFR and issued VFR traffic; not on frequency.

Attributes
ACN	755007
Time
Date	200709
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : fuz.vortac
State Reference	TX
Altitude	msl single value : 11000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zfw.artcc
Operator	common carrier : air carrier
Make Model Name	Airbus Industrie Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude
Route In Use	arrival star : n/s
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zfw.artcc
Operator	general aviation : personal
Make Model Name	Learjet 35
Operating Under FAR Part	Part 91
Flight Phase	climbout : intermediate altitude
Flight Plan	VFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller non radar : 20 controller radar : 18 controller time certified in position1 : 9 controller time certified in position2 : 9
ASRS Report	755007
Events
Anomaly	conflict : airborne critical
Independent Detector	atc equipment : conflict alert aircraft equipment : tcas other controllera
Resolutory Action	controller : issued new clearance controller : issued alert flight crew : took evasive action
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Ambiguous

Narrative:

I was working seavr low radar position (37) when air carrier X checked on to my frequency at XA45 UTC. Air carrier X was issued the clearance to cross sasie intersection at and maintain 90. Aircraft Y was pvd'd on my scope at XA51:45 UTC. My radar associate told me aircraft Y would remain VFR on a 90 degree heading. I issued traffic to air carrier X reference aircraft Y at XA52:10 UTC. At XA53:38 I told air carrier X that the learjet was VFR turning to heading 090 degrees. I issued air carrier X traffic again at XA53:10. I then asked air carrier X if he had traffic in sight; because air carrier X said he had traffic on TCAS. When air carrier X replied he did not have traffic in sight just on TCAS I suggested air carrier X turn 30 degrees right immediately since I was not in radio contact with aircraft Y. Air carrier X replied he had traffic in TCAS and had missed the traffic. Air carrier X stated he was turning back on course and returning to a normal rate of descent. At XA53:53 I cleared air carrier X direct sasie. At XA54:00 aircraft Y made initial call on frequency.

Original NASA ASRS Text

Title: ZFW CTLR DESCRIBED CONFLICT AT 11000 BETWEEN IFR AND ISSUED VFR TFC; NOT ON FREQ.

Narrative: I WAS WORKING SEAVR LOW RADAR POS (37) WHEN ACR X CHKED ON TO MY FREQ AT XA45 UTC. ACR X WAS ISSUED THE CLRNC TO CROSS SASIE INTXN AT AND MAINTAIN 90. ACFT Y WAS PVD'D ON MY SCOPE AT XA51:45 UTC. MY RADAR ASSOCIATE TOLD ME ACFT Y WOULD REMAIN VFR ON A 90 DEG HDG. I ISSUED TFC TO ACR X REF ACFT Y AT XA52:10 UTC. AT XA53:38 I TOLD ACR X THAT THE LEARJET WAS VFR TURNING TO HDG 090 DEGS. I ISSUED ACR X TFC AGAIN AT XA53:10. I THEN ASKED ACR X IF HE HAD TFC IN SIGHT; BECAUSE ACR X SAID HE HAD TFC ON TCAS. WHEN ACR X REPLIED HE DID NOT HAVE TFC IN SIGHT JUST ON TCAS I SUGGESTED ACR X TURN 30 DEGS R IMMEDIATELY SINCE I WAS NOT IN RADIO CONTACT WITH ACFT Y. ACR X REPLIED HE HAD TFC IN TCAS AND HAD MISSED THE TFC. ACR X STATED HE WAS TURNING BACK ON COURSE AND RETURNING TO A NORMAL RATE OF DSCNT. AT XA53:53 I CLRED ACR X DIRECT SASIE. AT XA54:00 ACFT Y MADE INITIAL CALL ON FREQ.

Data retrieved from NASA's ASRS site as of January 2009 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.