B737 crew and ZDC controller was confused by aircraft with similar call signs.

Attributes
ACN	491970
Time
Date	200011
Day	Sat
Local Time Of Day	1801 To 2400
Place
Locale Reference	navaid : rdu.ils
State Reference	NC
Altitude	msl bound lower : 31000 msl bound upper : 33000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zdc.artcc
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise : level cruise : enroute altitude change
Route In Use	enroute airway : j52.airway
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zdc.artcc
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise : enroute altitude change
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 120 flight time total : 7800 flight time type : 1800
ASRS Report	491970
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Anomaly	non adherence : published procedure non adherence : far other anomaly other
Independent Detector	other controllera other flight crewa other flight crewb
Resolutory Action	controller : issued alert controller : issued new clearance
Supplementary
Problem Areas	Company FAA ATC Human Performance
Primary Problem	ATC Human Performance

Narrative:

Altitude clearance confusion: while cruising at FL330, center cleared us (flight abcd) down to FL310. Center was also working another aircraft (flight abce) on another frequency. Center's intentions was to descend abce down to FL310 not us, abcd, however center used our call sign and I responded to the clearance with our call sign. While passing FL320 center queried us, abcd, about our altitude. I reminded him that he cleared us down to FL310. He stated that the clearance was for abce not abcd (us). He then cleared us to continue descent to FL310. WX was clear and there were no TCASII alerts. Center confused our call sign with another call sign. After the confusion center advised us of similar sounding call signs.

Original NASA ASRS Text

Title: B737 CREW AND ZDC CTLR WAS CONFUSED BY ACFT WITH SIMILAR CALL SIGNS.

Narrative: ALT CLRNC CONFUSION: WHILE CRUISING AT FL330, CTR CLRED US (FLT ABCD) DOWN TO FL310. CTR WAS ALSO WORKING ANOTHER ACFT (FLT ABCE) ON ANOTHER FREQ. CTR'S INTENTIONS WAS TO DSND ABCE DOWN TO FL310 NOT US, ABCD, HOWEVER CTR USED OUR CALL SIGN AND I RESPONDED TO THE CLRNC WITH OUR CALL SIGN. WHILE PASSING FL320 CTR QUERIED US, ABCD, ABOUT OUR ALT. I REMINDED HIM THAT HE CLRED US DOWN TO FL310. HE STATED THAT THE CLRNC WAS FOR ABCE NOT ABCD (US). HE THEN CLRED US TO CONTINUE DSCNT TO FL310. WX WAS CLR AND THERE WERE NO TCASII ALERTS. CTR CONFUSED OUR CALL SIGN WITH ANOTHER CALL SIGN. AFTER THE CONFUSION CTR ADVISED US OF SIMILAR SOUNDING CALL SIGNS.

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.