B727 crew had altitude deviation arriving at dfw.

Attributes
ACN	474100
Time
Date	200005
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : dfw.airport
State Reference	TX
Altitude	msl bound lower : 10700 msl bound upper : 11000
Environment
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B727-200
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	474100
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
ASRS Report	474094
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : returned to assigned altitude
Consequence	other other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

Altitude deviation. Stabilizer trim illuminated at 11000 ft. As I was retrimming the aircraft, it started a descent and may have gone more than 300 ft low. Supplemental information from acn 474099: stabilizer trim light illuminated at 11000 ft. Captain retrimmed the aircraft as it rolled into a turn and began a descent. Before the descent was arrested, the aircraft may have descended more than 300 ft low.

Original NASA ASRS Text

Title: B727 CREW HAD ALTDEV ARRIVING AT DFW.

Narrative: ALTDEV. STABILIZER TRIM ILLUMINATED AT 11000 FT. AS I WAS RETRIMMING THE ACFT, IT STARTED A DSCNT AND MAY HAVE GONE MORE THAN 300 FT LOW. SUPPLEMENTAL INFO FROM ACN 474099: STABILIZER TRIM LIGHT ILLUMINATED AT 11000 FT. CAPT RETRIMMED THE ACFT AS IT ROLLED INTO A TURN AND BEGAN A DSCNT. BEFORE THE DSCNT WAS ARRESTED, THE ACFT MAY HAVE DSNDED MORE THAN 300 FT LOW.

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.