Aircraft descended below intended altitude issued by controller. No conflict.

Attributes
ACN	160053
Time
Date	199010
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : mlc
State Reference	OK
Altitude	msl bound lower : 11000 msl bound upper : 13000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zfw
Operator	common carrier : air carrier
Make Model Name	Light Transport, High Wing, 2 Turboprop Eng
Navigation In Use	Other
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 250 flight time total : 6900 flight time type : 1000
ASRS Report	160053
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 280 flight time total : 6300 flight time type : 280
ASRS Report	160050
Events
Anomaly	altitude deviation : overshoot non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were being radar vectored at the time of occurrence. Center gave us and the captain read back fly heading 030 degrees and descend and maintain 11000'. There was some light turbulence during the descent, so the captain turned on the seat belt sign. While the captain was talking to the passenger on the P/a, center requested that we expedite our descent through 13000 to maintain 11000', so I acknowledged. While passing 12000', we were instructed to immediately climb and maintain 13000', so we expedited to 13000' and the controller said we were cleared to 13000, not 11000'. The captain came back and said he read back 11000'. That was the end of the conflict.

Original NASA ASRS Text

Title: ACFT DESCENDED BELOW INTENDED ALT ISSUED BY CTLR. NO CONFLICT.

Narrative: WE WERE BEING RADAR VECTORED AT THE TIME OF OCCURRENCE. CENTER GAVE US AND THE CAPT READ BACK FLY HDG 030 DEGS AND DSND AND MAINTAIN 11000'. THERE WAS SOME LIGHT TURB DURING THE DSNT, SO THE CAPT TURNED ON THE SEAT BELT SIGN. WHILE THE CAPT WAS TALKING TO THE PAX ON THE P/A, CENTER REQUESTED THAT WE EXPEDITE OUR DSNT THROUGH 13000 TO MAINTAIN 11000', SO I ACKNOWLEDGED. WHILE PASSING 12000', WE WERE INSTRUCTED TO IMMEDIATELY CLB AND MAINTAIN 13000', SO WE EXPEDITED TO 13000' AND THE CTLR SAID WE WERE CLRED TO 13000, NOT 11000'. THE CAPT CAME BACK AND SAID HE READ BACK 11000'. THAT WAS THE END OF THE CONFLICT.

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.