ZTL controller described a loss of separation when two company aircraft accepted the wrong ATC clear...

Narrative:

Air carrier X was initially climbed to FL330 on dawgs departure on J14. Air carrier Y was stopped at FL310 on the debie..bgred departure off clt. Air carrier Y was stopped under slow citation on same route at FL320. With trainer and d-side; collectively agreed to stop air carrier X at FL300 and turned air carrier Y to allow to get to requested altitude quicker. Clearance was given to stop air carrier X at FL300 and an air carrier Z; 50 miles ahead on J14; read the clearance back and neither of us caught the readback error nor did the air carrier X. The halo was on air carrier Y at FL310 with air carrier X passing underneath when saw the air carrier X go through FL304 and immediately questioned his clearance and the air carrier Z said they thought that was them and they were the ones who read it back. Air carrier X said they were still climbing to FL330. Therefore a loss of vertical separation occurred between air carrier X and air carrier Y. This all occurred after a very busy time when all clt arrivals in the stram had to be vectored with s-turns to bleed off high tma numbers.

Original NASA ASRS Text

Title: ZTL Controller described a loss of separation when two company aircraft accepted the wrong ATC clearance causing the separation loss; one reporter claiming the subject company pilots frequently confuse their call signs.

Narrative: Air Carrier X was initially climbed to FL330 on DAWGS departure on J14. Air Carrier Y was stopped at FL310 on the Debie..Bgred departure off CLT. Air Carrier Y was stopped under slow Citation on same route at FL320. with trainer and D-Side; collectively agreed to stop Air Carrier X at FL300 and turned Air Carrier Y to allow to get to requested altitude quicker. Clearance was given to stop Air Carrier X at FL300 and an Air Carrier Z; 50 miles ahead on J14; read the clearance back and neither of us caught the readback error nor did the Air Carrier X. The HALO was on Air Carrier Y at FL310 with Air Carrier X passing underneath when saw the Air Carrier X go through FL304 and immediately questioned his clearance and the Air Carrier Z said they thought that was them and they were the ones who read it back. Air Carrier X said they were still climbing to FL330. Therefore a loss of vertical separation occurred between Air Carrier X and Air Carrier Y. This all occurred after a very busy time when all CLT arrivals in the stram had to be vectored with S-turns to bleed off high TMA numbers.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	1113379
Time
Date	201309
Local Time Of Day	0001-0600
Place
Locale Reference	ZTL.ARTCC
State Reference	GA
Aircraft 1
Make Model Name	MD-88
Flight Phase	Climb
Route In Use	SID DAWGS
Flight Plan	IFR
Aircraft 2
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Plan	IFR
Person 1
Function	Enroute
Qualification	Air Traffic Control Developmental
Person 2
Function	Enroute
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy

ZTL controller described a loss of separation when two company aircraft accepted the wrong ATC clearance causing the separation loss; one reporter claiming the subject company pilots frequently confuse their call signs.