Air carrier X had less than standard separation from air carrier Y system error.

Attributes
ACN	163127
Time
Date	199011
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : ind
State Reference	IN
Altitude	msl bound lower : 21000 msl bound upper : 22000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : direct
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 3
ASRS Report	163127
Person 2
Affiliation	government : faa
Function	controller : handoff position
Qualification	controller : radar
Experience	controller radar : 19
ASRS Report	162781
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	faa : investigated
Miss Distance	horizontal : 22000 vertical : 300
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Radar trnee assigned air carrier X an altitude that put it I confliction with air carrier Y . I did not hear this. Tracker and manual controller also did not hear it. By the time I realized what happened I didn't have time to maintain vertical sep. Mode 'C' on the clber was lagging by more than usual and that didn't help. Frequency congestion was also bad due to local approach controllers using multiple frequencys. The trnee was not overloaded but frequency congestion was unnecessary and a problem. The approach controllers at this time of day just start using those split frequencys west/O being told. The incident occurred in a combined serious situation, still not a problem. Supplemental information from acn 162781. Heavy traffic, training, trnee not fully aware of traffic. Air carrier Y level at FL220 northbound, air carrier X westbound climbing to FL230. Trnee failed to stop climb at FL210. Instrument tried to stop climb only to find out mode 'C' was 800' behind actual altitude.

Original NASA ASRS Text

Title: ACR X HAD LESS THAN STANDARD SEPARATION FROM ACR Y SYSTEM ERROR.

Narrative: RADAR TRNEE ASSIGNED ACR X AN ALT THAT PUT IT I CONFLICTION WITH ACR Y . I DID NOT HEAR THIS. TRACKER AND MANUAL CTLR ALSO DID NOT HEAR IT. BY THE TIME I REALIZED WHAT HAPPENED I DIDN'T HAVE TIME TO MAINTAIN VERT SEP. MODE 'C' ON THE CLBER WAS LAGGING BY MORE THAN USUAL AND THAT DIDN'T HELP. FREQ CONGESTION WAS ALSO BAD DUE TO LCL APCH CTLRS USING MULTIPLE FREQS. THE TRNEE WAS NOT OVERLOADED BUT FREQ CONGESTION WAS UNNECESSARY AND A PROB. THE APCH CTLRS AT THIS TIME OF DAY JUST START USING THOSE SPLIT FREQS W/O BEING TOLD. THE INCIDENT OCCURRED IN A COMBINED SERIOUS SITUATION, STILL NOT A PROB. SUPPLEMENTAL INFO FROM ACN 162781. HVY TFC, TRNING, TRNEE NOT FULLY AWARE OF TFC. ACR Y LEVEL AT FL220 NBND, ACR X WBND CLBING TO FL230. TRNEE FAILED TO STOP CLB AT FL210. INSTR TRIED TO STOP CLB ONLY TO FIND OUT MODE 'C' WAS 800' BEHIND ACTUAL ALT.

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.