An airbus A320 flight crew accepted a clearance intended for a similar call sign aircraft.

Attributes
ACN	454760
Time
Date	199911
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : oma.airport
State Reference	NE
Altitude	msl single value : 37000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdv.artcc
Operator	common carrier : air carrier
Make Model Name	A320
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : level
Route In Use	enroute : on vectors
Flight Plan	VFR
Aircraft 2
Controlling Facilities	artcc : zdv.artcc
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 15000 flight time type : 900
ASRS Report	454760
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Events
Anomaly	other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance

Narrative:

ZDV issued clearance for aircraft X left 20 degrees pilot read back left 20 degrees and turned left 20 degrees. Center later asked what was our heading. We replied 042 degrees and said clearance was given to us to turn left 20 degrees. Center said clearance was for aircraft Y to turn left 20 degrees. We were then vectored 20 degrees to left then on course. No conflict was indicated by center, however, had he not noticed our deviation, a conflict would have arose. Controller should have warned us that a similar call sign was on frequency. Also, we read back clearance with full call sign and controller should have noticed error.

Original NASA ASRS Text

Title: AN AIRBUS A320 FLC ACCEPTED A CLRNC INTENDED FOR A SIMILAR CALL SIGN ACFT.

Narrative: ZDV ISSUED CLRNC FOR ACFT X L 20 DEGS PLT READ BACK L 20 DEGS AND TURNED L 20 DEGS. CTR LATER ASKED WHAT WAS OUR HDG. WE REPLIED 042 DEGS AND SAID CLRNC WAS GIVEN TO US TO TURN L 20 DEGS. CTR SAID CLRNC WAS FOR ACFT Y TO TURN L 20 DEGS. WE WERE THEN VECTORED 20 DEGS TO L THEN ON COURSE. NO CONFLICT WAS INDICATED BY CTR, HOWEVER, HAD HE NOT NOTICED OUR DEV, A CONFLICT WOULD HAVE AROSE. CTLR SHOULD HAVE WARNED US THAT A SIMILAR CALL SIGN WAS ON FREQ. ALSO, WE READ BACK CLRNC WITH FULL CALL SIGN AND CTLR SHOULD HAVE NOTICED ERROR.

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.