Aircraft 2 had less than standard separation from aircraft 1. System error.

Attributes
ACN	113092
Time
Date	198906
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zid
State Reference	IN
Altitude	msl bound lower : 31000 msl bound upper : 33000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : non radar
Qualification	controller : non radar
Experience	controller non radar : 2
ASRS Report	113092
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation
Independent Detector	other other : unspecified atc
Resolutory Action	none taken : detected after the fact
Consequence	faa : investigated
Miss Distance	vertical : 1500
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Two aircraft. Aircraft 1 wbound at FL330, aircraft 2 southbound at FL310. Aircraft 2 southbound misread a clearance for another aircraft. Controller didn't catch readback. Southbound climbed to FL330. Separation was lost.

Original NASA ASRS Text

Title: ACFT 2 HAD LESS THAN STANDARD SEPARATION FROM ACFT 1. SYSTEM ERROR.

Narrative: TWO ACFT. ACFT 1 WBOUND AT FL330, ACFT 2 SBND AT FL310. ACFT 2 SBND MISREAD A CLRNC FOR ANOTHER ACFT. CTLR DIDN'T CATCH READBACK. SBND CLIMBED TO FL330. SEPARATION WAS LOST.

Data retrieved from NASA's ASRS site as of August 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.