Air carrier X unauthorized descent through assigned altitude. Altitude deviation.

Attributes
ACN	294020
Time
Date	199501
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : atl
State Reference	GA
Altitude	msl bound lower : 11500 msl bound upper : 13000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	enroute : direct enroute airway : ztl
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 9500 flight time type : 7000
ASRS Report	294020
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Air carrier X cruising at FL200. When we received a clearance to descend to 13000 ft and cross canuk intersection at 11000 ft, we began a slow descent and at 11500 ft the controller asked our altitude. I responded 11300 ft descending to 11000 ft. The controller said we were only cleared to 13000 ft and expect to cross canuk at 11000 ft. The controller then said maintain 11000 ft and nothing else was said about the situation.

Original NASA ASRS Text

Title: ACR X UNAUTH DSCNT THROUGH ASSIGNED ALT. ALTDEV.

Narrative: ACR X CRUISING AT FL200. WHEN WE RECEIVED A CLRNC TO DSND TO 13000 FT AND CROSS CANUK INTXN AT 11000 FT, WE BEGAN A SLOW DSCNT AND AT 11500 FT THE CTLR ASKED OUR ALT. I RESPONDED 11300 FT DSNDING TO 11000 FT. THE CTLR SAID WE WERE ONLY CLRED TO 13000 FT AND EXPECT TO CROSS CANUK AT 11000 FT. THE CTLR THEN SAID MAINTAIN 11000 FT AND NOTHING ELSE WAS SAID ABOUT THE SIT.

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.