Altitude clearance disagreement between controller and crew.

Attributes
ACN	480860
Time
Date	200007
Day	Mon
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : atl.airport
State Reference	GA
Altitude	msl bound lower : 12000 msl bound upper : 15000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : ztl.artcc
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : vacating altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain
Qualification	pilot : multi engine pilot : instrument pilot : flight engineer pilot : commercial pilot : atp
Experience	flight time last 90 days : 98 flight time total : 11007 flight time type : 1810
ASRS Report	480860
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Anomaly	other anomaly other
Independent Detector	other controllerb other flight crewa
Resolutory Action	controller : issued new clearance
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	ATC Human Performance

Narrative:

ZTL gave us a descent to 12000 ft 40 mi north of atl. Passing 13000 ft, center asked what altitude we were descending to. I answered 12000 ft. ZTL's response was that clearance was to 15000 ft. I answered that I read back 12000 ft on the initial clearance and I would start a climb. ZTL responded with clearance to level at 13000 ft. 30 seconds later, a clearance to 12000 ft was given and a frequency change to atl approach. Both pilots heard 12000 ft on the initial clearance and I read back 12000 ft. Controller said she did not hear my 12000 ft call. Crew fatigue was not a factor, nor were cockpit conversations of other radio communications. I am concerned with controllers not paying attention to the readback of clrncs and the FAA policy that correct readback acknowledgements by pilots to controllers are not the responsibility of the controller. Readbacks are the only way to verify clrncs!

Original NASA ASRS Text

Title: ALT CLRNC DISAGREEMENT BTWN CTLR AND CREW.

Narrative: ZTL GAVE US A DSCNT TO 12000 FT 40 MI N OF ATL. PASSING 13000 FT, CTR ASKED WHAT ALT WE WERE DSNDING TO. I ANSWERED 12000 FT. ZTL'S RESPONSE WAS THAT CLRNC WAS TO 15000 FT. I ANSWERED THAT I READ BACK 12000 FT ON THE INITIAL CLRNC AND I WOULD START A CLB. ZTL RESPONDED WITH CLRNC TO LEVEL AT 13000 FT. 30 SECONDS LATER, A CLRNC TO 12000 FT WAS GIVEN AND A FREQ CHANGE TO ATL APCH. BOTH PLTS HEARD 12000 FT ON THE INITIAL CLRNC AND I READ BACK 12000 FT. CTLR SAID SHE DID NOT HEAR MY 12000 FT CALL. CREW FATIGUE WAS NOT A FACTOR, NOR WERE COCKPIT CONVERSATIONS OF OTHER RADIO COMS. I AM CONCERNED WITH CTLRS NOT PAYING ATTN TO THE READBACK OF CLRNCS AND THE FAA POLICY THAT CORRECT READBACK ACKNOWLEDGEMENTS BY PLTS TO CTLRS ARE NOT THE RESPONSIBILITY OF THE CTLR. READBACKS ARE THE ONLY WAY TO VERIFY CLRNCS!

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.