Less than standard separation between two corp aircraft. Operational error.

Attributes
ACN	98913
Time
Date	198811
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : mke airport : rac
State Reference	WI
Altitude	msl bound lower : 12900 msl bound upper : 13000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau tracon : mke
Operator	general aviation : corporate
Make Model Name	Light Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	general aviation : corporate
Make Model Name	Small Transport, Low Wing, 2 Turboprop Eng
Flight Phase	climbout : intermediate altitude cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : departure
Qualification	controller : radar
ASRS Report	98913
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	atc equipment other atc equipment : unspecified
Resolutory Action	none taken : insufficient time none taken : unable
Consequence	faa : investigated
Miss Distance	horizontal : 20400 vertical : 100
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error Inter Facility Coordination Failure

Narrative:

I was working east departure radar at milwaukee ATC tower. I was working corp jet X eastbound off mke, and corp aircraft Y off racine eastbound. I had the aircraft on parallel headings with X climbing to 13000'. I inadvertently climbed corp Y to 13000' instead of X and told Y to contact center. Center computer error detection equipment alarmed. Center turned X northeast away from corp Y. Error detection equipment showed 3.4 mi and 100' vertical sep.

Original NASA ASRS Text

Title: LESS THAN STANDARD SEPARATION BETWEEN TWO CORP ACFT. OPERATIONAL ERROR.

Narrative: I WAS WORKING E DEP RADAR AT MILWAUKEE ATC TWR. I WAS WORKING CORP JET X EBND OFF MKE, AND CORP ACFT Y OFF RACINE EBND. I HAD THE ACFT ON PARALLEL HDGS WITH X CLBING TO 13000'. I INADVERTENTLY CLBED CORP Y TO 13000' INSTEAD OF X AND TOLD Y TO CONTACT CENTER. CENTER COMPUTER ERROR DETECTION EQUIPMENT ALARMED. CENTER TURNED X NE AWAY FROM CORP Y. ERROR DETECTION EQUIPMENT SHOWED 3.4 MI AND 100' VERT SEP.

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.