B727 was cleared to descend to FL310 on 290 degree heading. Got a TCASII TA and saw target ahead at FL330. Advised center turning left to avoid when another controller said to maintain FL350. Then noting the flight crew altitude, issued clearance to turn left 040 degrees.

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Attributes
ACN	365803
Time
Date	199704
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : fbr
State Reference	WY
Altitude	msl bound lower : 34000 msl bound upper : 34000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zlc tower : ord
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : atp pilot : instrument pilot : private
Experience	flight time last 90 days : 185 flight time total : 11000 flight time type : 6000
ASRS Report	365803
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	conflict : airborne less severe non adherence : far non adherence : published procedure non adherence : required legal separation
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	controller : issued new clearance flight crew : took evasive action other
Consequence	Other
Miss Distance	vertical : 1000
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Flight was en route cvg-slc and was given a descent clearance from cruise altitude of FL350 to FL310 as well as a turn to maintain heading of 290 degrees. The aircraft was beginning the descent when a TA and the aural 'traffic' alert was received showing a target ahead at FL330. Descent was stopped at FL340 and the crew inquired with ZLC about the traffic ahead and slightly right of the nose. The captain of flight advised ZLC that he was initiating a turn to the left in avoidance just as a new controller voice from center advised to 'maintain FL350.' upon realizing that flight had already descended, the same controller then commanded 'turn 40 degrees left' which was what the flight crew had initiated. Another company aircraft was observed to pass to the right and just below at FL330.

Original NASA ASRS Text

Title: B727 WAS CLRED TO DSND TO FL310 ON 290 DEG HDG. GOT A TCASII TA AND SAW TARGET AHEAD AT FL330. ADVISED CTR TURNING L TO AVOID WHEN ANOTHER CTLR SAID TO MAINTAIN FL350. THEN NOTING THE FLC ALT, ISSUED CLRNC TO TURN L 040 DEGS.

Narrative: FLT WAS ENRTE CVG-SLC AND WAS GIVEN A DSCNT CLRNC FROM CRUISE ALT OF FL350 TO FL310 AS WELL AS A TURN TO MAINTAIN HDG OF 290 DEGS. THE ACFT WAS BEGINNING THE DSCNT WHEN A TA AND THE AURAL 'TFC' ALERT WAS RECEIVED SHOWING A TARGET AHEAD AT FL330. DSCNT WAS STOPPED AT FL340 AND THE CREW INQUIRED WITH ZLC ABOUT THE TFC AHEAD AND SLIGHTLY R OF THE NOSE. THE CAPT OF FLT ADVISED ZLC THAT HE WAS INITIATING A TURN TO THE L IN AVOIDANCE JUST AS A NEW CTLR VOICE FROM CTR ADVISED TO 'MAINTAIN FL350.' UPON REALIZING THAT FLT HAD ALREADY DSNDED, THE SAME CTLR THEN COMMANDED 'TURN 40 DEGS L' WHICH WAS WHAT THE FLC HAD INITIATED. ANOTHER COMPANY ACFT WAS OBSERVED TO PASS TO THE R AND JUST BELOW AT FL330.

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.