Tys approach controller experienced operational error at 3000 ft when vectoring aircraft.

Attributes
ACN	692000
Time
Date	200603
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : vxv.vortac
State Reference	TN
Altitude	msl single value : 3000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : tys.tracon
Operator	general aviation : corporate
Make Model Name	Learjet 35
Operating Under FAR Part	Part 91
Navigation In Use	other vortac
Flight Phase	descent : approach
Route In Use	approach : visual
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : tys.tracon
Make Model Name	Baron 58/58TC
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Route In Use	approach : visual
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Experience	controller military : 3 controller radar : 18 controller time certified in position1 : 18
ASRS Report	692000
Person 2
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	atc equipment : conflict alert aircraft equipment : tcas other controllera
Resolutory Action	none taken : detected after the fact
Consequence	faa : investigated
Miss Distance	horizontal : 7500 vertical : 500
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

While working radar I assigned the baron at 3000 ft; heading 070 degrees to lock down his heading to provide passing and diverging separation with his traffic. Learjet who was at 4000 ft assigned heading 060 degrees. I turned the learjet to heading 090 degrees inside the baron. After the learjet crossed inside and ahead of the baron I discontinued vertical separation and descended the learjet to 2500 ft. I then proceeded to turn the baron right at the learjet and told the baron about the traffic. 10 seconds later visual separation was obtained and both aircraft were switched to tower frequency. I then observed the learjet level off at 3000 ft and called the tower; overhearing learjet having a gear problem. Unheard was a TCAS RA. Tower advised of visual separation being used by/provided by baron. I was told of operational error because I misinterped passing and diverging rule far 7110.65 paragraph 5-5-7.

Original NASA ASRS Text

Title: TYS APCH CTLR EXPERIENCED OPERROR AT 3000 FT WHEN VECTORING ACFT.

Narrative: WHILE WORKING RADAR I ASSIGNED THE BARON AT 3000 FT; HDG 070 DEGS TO LOCK DOWN HIS HDG TO PROVIDE PASSING AND DIVERGING SEPARATION WITH HIS TFC. LEARJET WHO WAS AT 4000 FT ASSIGNED HDG 060 DEGS. I TURNED THE LEARJET TO HDG 090 DEGS INSIDE THE BARON. AFTER THE LEARJET CROSSED INSIDE AND AHEAD OF THE BARON I DISCONTINUED VERT SEPARATION AND DSNDED THE LEARJET TO 2500 FT. I THEN PROCEEDED TO TURN THE BARON RIGHT AT THE LEARJET AND TOLD THE BARON ABOUT THE TFC. 10 SECONDS LATER VISUAL SEPARATION WAS OBTAINED AND BOTH ACFT WERE SWITCHED TO TWR FREQ. I THEN OBSERVED THE LEARJET LEVEL OFF AT 3000 FT AND CALLED THE TWR; OVERHEARING LEARJET HAVING A GEAR PROB. UNHEARD WAS A TCAS RA. TWR ADVISED OF VISUAL SEPARATION BEING USED BY/PROVIDED BY BARON. I WAS TOLD OF OPERROR BECAUSE I MISINTERPED PASSING AND DIVERGING RULE FAR 7110.65 PARAGRAPH 5-5-7.

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.