ARTCC radar controller issued descend clearance to the wrong aircraft.

Attributes
ACN	158087
Time
Date	199009
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : den
State Reference	CO
Altitude	msl bound lower : 30650 msl bound upper : 31000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdv
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	descent other
Route In Use	arrival other arrival star : star enroute airway : zdv
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Route In Use	arrival other arrival star : star
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : instrument pilot : atp pilot : commercial
Experience	flight time last 90 days : 240 flight time total : 7000 flight time type : 800
ASRS Report	158087
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
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	Other
Miss Distance	vertical : 1350
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

At FL310 approximately 50 NM west of drako intersection with communication established with den center, at xx:42Z den center cleared our flight, widebody transport to descend to FL290, pilot's discretion down to FL240. We received and acknowledged the ATC clearance and our transmission was acknowledged. We then initiated a descent to comply with the clearance. At FL30.6 ATC issued a traffic advisory to stop descent and return to FL310, citing traffic below us at FL290. We complied with the new clearance while acknowledging it. When the frequency cleared, we asked center for clarification. The controller apologized for the mistaken clearance intended for another aircraft and the misunderstanding involved.

Original NASA ASRS Text

Title: ARTCC RADAR CTLR ISSUED DESCEND CLRNC TO THE WRONG ACFT.

Narrative: AT FL310 APPROX 50 NM W OF DRAKO INTXN WITH COM ESTABLISHED WITH DEN CTR, AT XX:42Z DEN CTR CLRED OUR FLT, WDB TO DSND TO FL290, PLT'S DISCRETION DOWN TO FL240. WE RECEIVED AND ACKNOWLEDGED THE ATC CLRNC AND OUR XMISSION WAS ACKNOWLEDGED. WE THEN INITIATED A DSNT TO COMPLY WITH THE CLRNC. AT FL30.6 ATC ISSUED A TFC ADVISORY TO STOP DSNT AND RETURN TO FL310, CITING TFC BELOW US AT FL290. WE COMPLIED WITH THE NEW CLRNC WHILE ACKNOWLEDGING IT. WHEN THE FREQ CLRED, WE ASKED CTR FOR CLARIFICATION. THE CTLR APOLOGIZED FOR THE MISTAKEN CLRNC INTENDED FOR ANOTHER ACFT AND THE MISUNDERSTANDING INVOLVED.

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.