Air carrier X descent through occupied altitude had less than standard separation from aircraft Y. S...

Attributes
ACN	199701
Time
Date	199201
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : spa
State Reference	SC
Altitude	msl bound lower : 12000 msl bound upper : 12500
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	enroute : direct enroute airway : clt
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	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 14500 flight time type : 1000
ASRS Report	199701
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Miss Distance	horizontal : 12000 vertical : 500
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Air carrier X descent into kgsp we were issued a clearance from 13000 ft to maintain 8000 ft. At approximately 12500 ft we were told to maintain 13000 ft and issued aircraft Y at 12000. We saw the traffic go by approximately 2-3 mi away and were issued a clearance to 10000 ft. We proceeded to a normal arrival in kgsp. Pilots and controllers have to keep a constant awareness for possible altitude conflicts.

Original NASA ASRS Text

Title: ACR X DSCNT THROUGH OCCUPIED ALT HAD LTSS FROM ACFT Y. SYS ERROR.

Narrative: ACR X DSCNT INTO KGSP WE WERE ISSUED A CLRNC FROM 13000 FT TO MAINTAIN 8000 FT. AT APPROX 12500 FT WE WERE TOLD TO MAINTAIN 13000 FT AND ISSUED ACFT Y AT 12000. WE SAW THE TFC GO BY APPROX 2-3 MI AWAY AND WERE ISSUED A CLRNC TO 10000 FT. WE PROCEEDED TO A NORMAL ARR IN KGSP. PLTS AND CTLRS HAVE TO KEEP A CONSTANT AWARENESS FOR POSSIBLE ALT CONFLICTS.

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.

Air carrier X descent through occupied altitude had less than standard separation from aircraft Y. System error.