ARTCC radar controller turned an air carrier jet 20 degrees left for separation from another air carrier aircraft at the same altitude. A TCASII RA was received by the first aircraft and it responded with a short climb and observed the traffic pass several mi away.

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Attributes
ACN	391125
Time
Date	199801
Day	Tue
Local Time Of Day	0001 To 0600
Place
Locale Reference	atc facility : ape
State Reference	OH
Altitude	msl bound lower : 41000 msl bound upper : 41200
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zid
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	enroute : on vectors enroute airway : zid
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 140 flight time total : 14500 flight time type : 850
ASRS Report	391125
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera
Resolutory Action	other
Consequence	Other
Miss Distance	horizontal : 24000 vertical : 200
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

In cruise at FL410, scheduled flight mia to dtw. Center controller requested a left turn of 20 degrees. I believe controller made a second transmission which was blocked by my readback of his initial instruction. This was immediately followed by a TCASII RA. We climbed 200 ft to comply with the RA and received immediate 'clear of conflict.' returned to FL410. We saw an air carrier flight pass off our right side at apparently same altitude. I believe both aircraft were at assigned altitudes. Separation was probably several mi. We didn't know about conflicting traffic until the TCASII RA. The controller should have told us of the conflict as soon as he recognized it. We could then have disconnected the autoplt and turned quickly instead of using the heading select mode of the FMS. His second transmission, which I blocked, may have included more urgent instructions. It should be noted that the system safe guards worked in this case. The controller recognized the conflict and the TCASII worked as advertised.

Original NASA ASRS Text

Title: ARTCC RADAR CTLR TURNED AN ACR JET 20 DEGS L FOR SEPARATION FROM ANOTHER ACR ACFT AT THE SAME ALT. A TCASII RA WAS RECEIVED BY THE FIRST ACFT AND IT RESPONDED WITH A SHORT CLB AND OBSERVED THE TFC PASS SEVERAL MI AWAY.

Narrative: IN CRUISE AT FL410, SCHEDULED FLT MIA TO DTW. CTR CTLR REQUESTED A L TURN OF 20 DEGS. I BELIEVE CTLR MADE A SECOND XMISSION WHICH WAS BLOCKED BY MY READBACK OF HIS INITIAL INSTRUCTION. THIS WAS IMMEDIATELY FOLLOWED BY A TCASII RA. WE CLBED 200 FT TO COMPLY WITH THE RA AND RECEIVED IMMEDIATE 'CLR OF CONFLICT.' RETURNED TO FL410. WE SAW AN ACR FLT PASS OFF OUR R SIDE AT APPARENTLY SAME ALT. I BELIEVE BOTH ACFT WERE AT ASSIGNED ALTS. SEPARATION WAS PROBABLY SEVERAL MI. WE DIDN'T KNOW ABOUT CONFLICTING TFC UNTIL THE TCASII RA. THE CTLR SHOULD HAVE TOLD US OF THE CONFLICT AS SOON AS HE RECOGNIZED IT. WE COULD THEN HAVE DISCONNECTED THE AUTOPLT AND TURNED QUICKLY INSTEAD OF USING THE HEADING SELECT MODE OF THE FMS. HIS SECOND XMISSION, WHICH I BLOCKED, MAY HAVE INCLUDED MORE URGENT INSTRUCTIONS. IT SHOULD BE NOTED THAT THE SYS SAFE GUARDS WORKED IN THIS CASE. THE CTLR RECOGNIZED THE CONFLICT AND THE TCASII WORKED AS ADVERTISED.

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.