Air carrier X TCASII RA evasive action descend from VFR aircraft. See and avoid concept.

Attributes
ACN	249968
Time
Date	199308
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : vuz
State Reference	AL
Altitude	msl bound lower : 11000 msl bound upper : 11400
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other
Route In Use	enroute : direct enroute airway : ztl
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	VFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 10
ASRS Report	249968
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 12000 vertical : 400
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

Air carrier X atl to gad to rqz to hsv had been cleared and leveled at 11000 ft. Head on VFR I was not working appeared opposite direction at 11400. I issued traffic to air carrier X. He rogered. He called ZTL again and advised he was getting a TCASII RA and descending. I told him to maintain 10000. No other aircraft involved and no problems occurred.

Original NASA ASRS Text

Title: ACR X TCASII RA EVASIVE ACTION DSND FROM VFR ACFT. SEE AND AVOID CONCEPT.

Narrative: ACR X ATL TO GAD TO RQZ TO HSV HAD BEEN CLRED AND LEVELED AT 11000 FT. HEAD ON VFR I WAS NOT WORKING APPEARED OPPOSITE DIRECTION AT 11400. I ISSUED TFC TO ACR X. HE ROGERED. HE CALLED ZTL AGAIN AND ADVISED HE WAS GETTING A TCASII RA AND DSNDING. I TOLD HIM TO MAINTAIN 10000. NO OTHER ACFT INVOLVED AND NO PROBS OCCURRED.

Data retrieved from NASA's ASRS site as of July 2007 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.