Cpr X had less than standard separation from air carrier Y. System error.

Attributes
ACN	187219
Time
Date	199108
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : mcw
State Reference	IA
Altitude	msl bound lower : 31000 msl bound upper : 31000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau tower : pwk
Operator	general aviation : corporate
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	cruise other
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	descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller non radar : 3 controller radar : 2
ASRS Report	187219
Person 2
Affiliation	government : faa
Function	controller : flight data
Qualification	controller : radar
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 : 19800 vertical : 800
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error Inter Facility Coordination Failure Intra Facility Coordination Failure

Narrative:

The incident began with my d-side initiating a handoff to the mcw sector on cpr Y, swbound from the coton sector into the mcw sector. Around this time I was vectoring an air carrier off course for intrail to ord when air carrier Y first checked on my frequency. I heard the aircraft state that he was level at FL330, expecting FL290 70 mi east (of mcw). However, I was not positive of the call sign, but because of my priority of duties, I did not immediately verify the call sign. Instead, I turned an air carrier to jvl so as to keep my string of ord inbounds evenly spaced. After doing so, I asked the aircraft calling center to say again. Air carrier Y checked back on, it confirmed that it was the aircraft I thought had previously called on. However, I understood from his first transmission that he was level at FL330, expecting FL290. I did not know that he had been given a descent clearance by mcw. By this time, msp had taken the handoff on cpr X. My d-side informed me that mcw had taken a pointout on cpr X and I was to keep the aircraft. Someone from the east area called on my landline. During that coordination, air carrier Y reported out of FL330. I did not hear this transmission. My d-side, who was listening to the frequency, heard it and brought it to my attention. I immediately told air carrier Y to maintain FL330 and to turn 30 degrees left. Air carrier Y did not respond. I then gave air carrier Y the clearance to maintain FL320 and to fly a 030 degree heading as well as calling out the traffic. Air carrier Y then reported out of 30400 ft. I called the traffic again to air carrier Y and then to cpr X. Cpr X reported the traffic in sight.

Original NASA ASRS Text

Title: CPR X HAD LTSS FROM ACR Y. SYS ERROR.

Narrative: THE INCIDENT BEGAN WITH MY D-SIDE INITIATING A HDOF TO THE MCW SECTOR ON CPR Y, SWBOUND FROM THE COTON SECTOR INTO THE MCW SECTOR. AROUND THIS TIME I WAS VECTORING AN ACR OFF COURSE FOR INTRAIL TO ORD WHEN ACR Y FIRST CHKED ON MY FREQ. I HEARD THE ACFT STATE THAT HE WAS LEVEL AT FL330, EXPECTING FL290 70 MI E (OF MCW). HOWEVER, I WAS NOT POSITIVE OF THE CALL SIGN, BUT BECAUSE OF MY PRIORITY OF DUTIES, I DID NOT IMMEDIATELY VERIFY THE CALL SIGN. INSTEAD, I TURNED AN ACR TO JVL SO AS TO KEEP MY STRING OF ORD INBOUNDS EVENLY SPACED. AFTER DOING SO, I ASKED THE ACFT CALLING CENTER TO SAY AGAIN. ACR Y CHKED BACK ON, IT CONFIRMED THAT IT WAS THE ACFT I THOUGHT HAD PREVIOUSLY CALLED ON. HOWEVER, I UNDERSTOOD FROM HIS FIRST XMISSION THAT HE WAS LEVEL AT FL330, EXPECTING FL290. I DID NOT KNOW THAT HE HAD BEEN GIVEN A DSCNT CLRNC BY MCW. BY THIS TIME, MSP HAD TAKEN THE HDOF ON CPR X. MY D-SIDE INFORMED ME THAT MCW HAD TAKEN A POINTOUT ON CPR X AND I WAS TO KEEP THE ACFT. SOMEONE FROM THE E AREA CALLED ON MY LANDLINE. DURING THAT COORD, ACR Y RPTED OUT OF FL330. I DID NOT HEAR THIS XMISSION. MY D-SIDE, WHO WAS LISTENING TO THE FREQ, HEARD IT AND BROUGHT IT TO MY ATTN. I IMMEDIATELY TOLD ACR Y TO MAINTAIN FL330 AND TO TURN 30 DEGS L. ACR Y DID NOT RESPOND. I THEN GAVE ACR Y THE CLRNC TO MAINTAIN FL320 AND TO FLY A 030 DEG HDG AS WELL AS CALLING OUT THE TFC. ACR Y THEN RPTED OUT OF 30400 FT. I CALLED THE TFC AGAIN TO ACR Y AND THEN TO CPR X. CPR X RPTED THE TFC IN SIGHT.

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.