Descent clearance issued to wrong aircraft.

Attributes
ACN	116694
Time
Date	198907
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : den
State Reference	CO
Altitude	msl bound lower : 16000 msl bound upper : 23000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdv tracon : den
Operator	common carrier : air carrier
Make Model Name	Medium Transport, High Wing, 2 Turboprop Eng
Navigation In Use	Other Other
Flight Phase	cruise other descent other
Route In Use	arrival other arrival star : star enroute airway : zdv
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 90 flight time total : 5500 flight time type : 200
ASRS Report	116694
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	other anomaly other other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance
Consequence	Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Air carrier xx departed riw for den approximately 30 min late. Passing abeam mbw VOR with ZDV 133.0, heard company air carrier xy on same frequency. Center then alerted us to similar call signs (xy about 2+30 late) (cpr-den). Approaching estus center cleared xx to 'descend now to 16,000''. We began 1000 FPM descent. Center then asked xx to descend at faster rate. We (xx) increased rate to 2000 FPM to 16,000. Center then handed us (xx) off to den approach. Note: xy approximately 15 mi ahead of xx and had not yet received descent clearance. Xx contacted den approach 120.2. Approach then cleared xx to 11,000'. (Now 10 north of estus). We leveled at 16,000 and queried the descent clearance (the terrain under airway is 10,000'-12,500' MSL). Approach admonished us for accepting clearance for xy then returned us to ZDV. Later conversation with PIC of xy confirmed that both center and approach made mistakes by switching and descending xx instead of xy. These flts normally operate 2 hours apart, so similar flight numbers do not normally conflict.

Original NASA ASRS Text

Title: DESCENT CLRNC ISSUED TO WRONG ACFT.

Narrative: ACR XX DEPARTED RIW FOR DEN APPROX 30 MIN LATE. PASSING ABEAM MBW VOR WITH ZDV 133.0, HEARD COMPANY ACR XY ON SAME FREQ. CENTER THEN ALERTED US TO SIMILAR CALL SIGNS (XY ABOUT 2+30 LATE) (CPR-DEN). APCHING ESTUS CENTER CLRED XX TO 'DSND NOW TO 16,000''. WE BEGAN 1000 FPM DSCNT. CENTER THEN ASKED XX TO DSND AT FASTER RATE. WE (XX) INCREASED RATE TO 2000 FPM TO 16,000. CENTER THEN HANDED US (XX) OFF TO DEN APCH. NOTE: XY APPROX 15 MI AHEAD OF XX AND HAD NOT YET RECEIVED DSCNT CLRNC. XX CONTACTED DEN APCH 120.2. APCH THEN CLRED XX TO 11,000'. (NOW 10 N OF ESTUS). WE LEVELED AT 16,000 AND QUERIED THE DSCNT CLRNC (THE TERRAIN UNDER AIRWAY IS 10,000'-12,500' MSL). APCH ADMONISHED US FOR ACCEPTING CLRNC FOR XY THEN RETURNED US TO ZDV. LATER CONVERSATION WITH PIC OF XY CONFIRMED THAT BOTH CENTER AND APCH MADE MISTAKES BY SWITCHING AND DESCENDING XX INSTEAD OF XY. THESE FLTS NORMALLY OPERATE 2 HRS APART, SO SIMILAR FLT NUMBERS DO NOT NORMALLY CONFLICT.

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.