A319 crew may have misheard clearance and descended to incorrect altitude.

Attributes
ACN	540589
Time
Date	200203
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	intersection : mayos
State Reference	NC
Altitude	msl bound lower : 32000 msl bound upper : 33000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : ztl.artcc
Operator	common carrier : air carrier
Make Model Name	A319
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : enroute altitude change
Route In Use	arrival star : n/s
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : cfi pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 60 flight time total : 15400 flight time type : 60
ASRS Report	540589
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	atc equipment other atc equipment : radar other controllera
Resolutory Action	controller : issued new clearance controller : issued advisory flight crew : returned to assigned altitude none taken : detected after the fact
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were given a clearance to descend from FL350 to FL310. We both used the altitude awareness procedures, and the captain acknowledged the clearance as 'descend to FL310.' as we were passing approximately FL320 the controller asked if we were maintaining FL330. This was the first time we had heard anything about FL330, and were both in complete agreement that we had been cleared to FL310. We climbed back to FL330. What bothers me about the current procedures of the controller not being responsible for hearing the readback correctly, is that we have lost another layer of error management. This needs to be changed. Everyone involved needs to be responsible for correct communications.

Original NASA ASRS Text

Title: A319 CREW MAY HAVE MISHEARD CLRNC AND DSNDED TO INCORRECT ALT.

Narrative: WE WERE GIVEN A CLRNC TO DSND FROM FL350 TO FL310. WE BOTH USED THE ALT AWARENESS PROCS, AND THE CAPT ACKNOWLEDGED THE CLRNC AS 'DSND TO FL310.' AS WE WERE PASSING APPROX FL320 THE CTLR ASKED IF WE WERE MAINTAINING FL330. THIS WAS THE FIRST TIME WE HAD HEARD ANYTHING ABOUT FL330, AND WERE BOTH IN COMPLETE AGREEMENT THAT WE HAD BEEN CLRED TO FL310. WE CLBED BACK TO FL330. WHAT BOTHERS ME ABOUT THE CURRENT PROCS OF THE CTLR NOT BEING RESPONSIBLE FOR HEARING THE READBACK CORRECTLY, IS THAT WE HAVE LOST ANOTHER LAYER OF ERROR MGMNT. THIS NEEDS TO BE CHANGED. EVERYONE INVOLVED NEEDS TO BE RESPONSIBLE FOR CORRECT COMS.

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.