Altitude excursion.

Attributes
ACN	144720
Time
Date	199004
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : tys
State Reference	TN
Altitude	msl bound lower : 29500 msl bound upper : 31000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : ztl
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other descent other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 150 flight time total : 8000 flight time type : 350
ASRS Report	144720
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : atp pilot : cfi pilot : flight engineer pilot : instrument
Experience	flight time last 90 days : 150 flight time total : 10000 flight time type : 3500
ASRS Report	144192
Events
Anomaly	altitude deviation : excursion from assigned altitude other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	Operational Deviation Pilot Deviation

Narrative:

I was flying the aircraft using the autoplt. Our flight was xyz 5. The captain read back a clearance to descend and maintain FL280. I began the descent from FL310 on the autoplt. At FL295 the ZTL controller said, 'flight xyz 5, what is your altitude.' I said, 'we're passing FL295 for FL280 as assigned.' he said, 'climb and maintain FL310, that was for YZ5. I should have told you I am working him on another frequency.' our confusion was caused by the similar sounding call signs, especially when pronounced 'xyz 5' and 'yz 5.' the confusion would have been avoided if we had been warned of the similar call sign. Supplemental information from acn 144192: the controllers never listen for the correct readback. I really can't blame the controller to any great degree, either. Generally, especially in the northeast, they're busier than a 1-ARMED paper hanger. This was a situation all to common. If we're not careful, and try to correct this, we're going to see an accident.

Original NASA ASRS Text

Title: ALT EXCURSION.

Narrative: I WAS FLYING THE ACFT USING THE AUTOPLT. OUR FLT WAS XYZ 5. THE CAPT READ BACK A CLRNC TO DSND AND MAINTAIN FL280. I BEGAN THE DSNT FROM FL310 ON THE AUTOPLT. AT FL295 THE ZTL CTLR SAID, 'FLT XYZ 5, WHAT IS YOUR ALT.' I SAID, 'WE'RE PASSING FL295 FOR FL280 AS ASSIGNED.' HE SAID, 'CLB AND MAINTAIN FL310, THAT WAS FOR YZ5. I SHOULD HAVE TOLD YOU I AM WORKING HIM ON ANOTHER FREQ.' OUR CONFUSION WAS CAUSED BY THE SIMILAR SOUNDING CALL SIGNS, ESPECIALLY WHEN PRONOUNCED 'XYZ 5' AND 'YZ 5.' THE CONFUSION WOULD HAVE BEEN AVOIDED IF WE HAD BEEN WARNED OF THE SIMILAR CALL SIGN. SUPPLEMENTAL INFO FROM ACN 144192: THE CTLRS NEVER LISTEN FOR THE CORRECT READBACK. I REALLY CAN'T BLAME THE CTLR TO ANY GREAT DEGREE, EITHER. GENERALLY, ESPECIALLY IN THE NE, THEY'RE BUSIER THAN A 1-ARMED PAPER HANGER. THIS WAS A SITUATION ALL TO COMMON. IF WE'RE NOT CAREFUL, AND TRY TO CORRECT THIS, WE'RE GOING TO SEE AN ACCIDENT.

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.