B737 flight crew reported becoming confused by similar sounding call signs during approach to atl an...

Narrative:

On the warrr 1 STAR to atl; we were at 12;000 ft; following the RNAV STAR. There was much congestion on the atl approach frequency; and we were assigned the runway 28 transition; which requires a downwind turn; during which are several step-down fixes. Another aircraft; (other carrier) was on the frequency; and both of us (company) and (other carrier) asked ATC to verify the call signs multiple times. At no time did I hear ATC warn 'similar-sounding call signs; use caution.' while still on the 45-degree angle to the RNAV downwind; I heard 'our call sign; descend and maintain 3000 ft.' I read back our call sign leaving 12;000 ft feet for 3000 ft.' as we were passing 6000 ft; ATC queried us; 'where are you going?' I replied; 'we are descending to 3000 ft as directed.' ATC told us to stop descent at I believe; 5000 ft; which we did. The first officer and I discussed the presence of (other carrier) on the same arrival. The controller seemed to have a very heavy workload this morning; as atl was using three westbound runways for approach and two runways for departures. ATC told us that 'we should know that he doesn't usually descend aircraft to 3000 feet so far from the airport.' I replied that we only complied with our ATC instruction; and had indeed read back the ATC clearance. After that event; we modified our call sign to 'company XXX; company'; to avoid further confusion with the similar-sounding 'other carrier XXXX'.in cases where ATC seems to be getting overwhelmed; we can help out by clarifying our call signs; and verifying the instructions by ATC. ATC did not respond to my readback of the descent to 3000; nor did ATC make any mention of my leaving 12;000 on the arrival. For our part; I believe that modifying the call signs to 'company XXXX; company' may have helped the controller avoid conflict.

Original NASA ASRS Text

Title: B737 flight crew reported becoming confused by similar sounding call signs during approach to ATL and mistakenly accepted a descent clearance meant for another aircraft.

Narrative: On the WARRR 1 STAR to ATL; we were at 12;000 ft; following the RNAV STAR. There was much congestion on the ATL Approach frequency; and we were assigned the Runway 28 transition; which requires a downwind turn; during which are several step-down fixes. Another aircraft; (other carrier) was on the frequency; and both of us (Company) and (other carrier) asked ATC to verify the call signs multiple times. At no time did I hear ATC warn 'Similar-sounding call signs; use caution.' While still on the 45-degree angle to the RNAV downwind; I heard 'our call sign; descend and maintain 3000 ft.' I read back our call sign leaving 12;000 ft feet for 3000 ft.' As we were passing 6000 ft; ATC queried us; 'where are you going?' I replied; 'we are descending to 3000 ft as directed.' ATC told us to stop descent at I believe; 5000 ft; which we did. The FO and I discussed the presence of (other carrier) on the same arrival. The Controller seemed to have a very heavy workload this morning; as ATL was using three westbound runways for approach and two runways for departures. ATC told us that 'we should know that he doesn't usually descend aircraft to 3000 feet so far from the airport.' I replied that we only complied with our ATC instruction; and had indeed read back the ATC clearance. After that event; we modified our call sign to 'Company XXX; Company'; to avoid further confusion with the similar-sounding 'other carrier XXXX'.In cases where ATC seems to be getting overwhelmed; we can help out by clarifying our call signs; and verifying the instructions by ATC. ATC did not respond to my readback of the descent to 3000; nor did ATC make any mention of my leaving 12;000 on the arrival. For our part; I believe that modifying the call signs to 'Company XXXX; Company' may have helped the Controller avoid conflict.

Data retrieved from NASA's ASRS site 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	1288664
Time
Date	201507
Local Time Of Day	0601-1200
Place
Locale Reference	ATL.Airport
State Reference	GA
Environment
Flight Conditions	VMC
Light	Dawn
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Route In Use	STAR WARRR 1
Flight Plan	IFR
Person 1
Function	Pilot Not Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 300 Flight Crew Type 9000
Person 2
Function	Pilot Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 130 Flight Crew Type 7200
Events
Anomaly	ATC Issue All Types Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Clearance

B737 flight crew reported becoming confused by similar sounding call signs during approach to atl and mistakenly accepted a descent clearance meant for another aircraft.