Flight crew initiates climb within ZME airspace confused by similar call sign.

Attributes
ACN	605677
Time
Date	200401
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : pxv.vortac
State Reference	IN
Altitude	msl single value : 29000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zme.artcc
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zme.artcc
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 60 flight time total : 8000 flight time type : 60
ASRS Report	605677
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	controller : issued advisory controller : issued new clearance
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Ambiguous

Narrative:

Aircraft was level at FL290 waiting for clearance to FL330. First officer called ZME and asked for higher. ZME responded immediately with a climb clearance to FL330. Crew thought they heard or did hear their call sign. Captain initiated climb to FL330. Passing FL290, ZME stated that the climb clearance was for company aircraft. Captain leveled aircraft at FL290. ZME then issued a climb to FL330 for aircraft X. Either ZME said the wrong call sign or the crew of aircraft X thought the climb was for them because of the immediate response of ZME following the request for higher -- expectation.

Original NASA ASRS Text

Title: FLT CREW INITIATES CLB WITHIN ZME AIRSPACE CONFUSED BY SIMILAR CALL SIGN.

Narrative: ACFT WAS LEVEL AT FL290 WAITING FOR CLRNC TO FL330. FO CALLED ZME AND ASKED FOR HIGHER. ZME RESPONDED IMMEDIATELY WITH A CLB CLRNC TO FL330. CREW THOUGHT THEY HEARD OR DID HEAR THEIR CALL SIGN. CAPT INITIATED CLB TO FL330. PASSING FL290, ZME STATED THAT THE CLB CLRNC WAS FOR COMPANY ACFT. CAPT LEVELED ACFT AT FL290. ZME THEN ISSUED A CLB TO FL330 FOR ACFT X. EITHER ZME SAID THE WRONG CALL SIGN OR THE CREW OF ACFT X THOUGHT THE CLB WAS FOR THEM BECAUSE OF THE IMMEDIATE RESPONSE OF ZME FOLLOWING THE REQUEST FOR HIGHER -- EXPECTATION.

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.