A fokker 100 flight crew had uncommanded stabilizer trim inputs on takeoff from dfw.

Attributes
ACN	443923
Time
Date	199907
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : dfw.airport
State Reference	TX
Altitude	msl single value : 2500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : dfw.tower
Operator	common carrier : air carrier
Make Model Name	Fokker 100
Operating Under FAR Part	Part 121
Flight Phase	climbout : initial
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : multi engine pilot : instrument
ASRS Report	443923
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : declared emergency flight crew : diverted to alternate flight crew : landed in emergency condition
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

Location: takeoff 2500 ft south of dfw runway 18L. After takeoff at about 2500 ft while hand flying, the stabilizer trim uncommanded started rolling back 'pitched up,' then started rolling forward 'pitched down.' the stabilizer trim wheel was moving forward. When I tried to move the stabilizer trim back with the yoke switches, the trim wheel would then start moving forward after I released the trim switches. I turned off the overhead stabilizer trim switches. Trimmed the aircraft with the trim wheel. Declared an emergency and returned to dfw. We landed 700 pounds overweight.

Original NASA ASRS Text

Title: A FOKKER 100 FLC HAD UNCOMMANDED STABILIZER TRIM INPUTS ON TKOF FROM DFW.

Narrative: LOCATION: TKOF 2500 FT S OF DFW RWY 18L. AFTER TKOF AT ABOUT 2500 FT WHILE HAND FLYING, THE STABILIZER TRIM UNCOMMANDED STARTED ROLLING BACK 'PITCHED UP,' THEN STARTED ROLLING FORWARD 'PITCHED DOWN.' THE STABILIZER TRIM WHEEL WAS MOVING FORWARD. WHEN I TRIED TO MOVE THE STABILIZER TRIM BACK WITH THE YOKE SWITCHES, THE TRIM WHEEL WOULD THEN START MOVING FORWARD AFTER I RELEASED THE TRIM SWITCHES. I TURNED OFF THE OVERHEAD STABILIZER TRIM SWITCHES. TRIMMED THE ACFT WITH THE TRIM WHEEL. DECLARED AN EMER AND RETURNED TO DFW. WE LANDED 700 LBS OVERWT.

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.