Light transport crew had aileron and rudder trim malfunction in ZBW class east airspace.

Attributes
ACN	479861
Time
Date	200007
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : orw.vor
State Reference	CT
Altitude	msl bound lower : 11700 msl bound upper : 12000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zbw.artcc
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Operating Under FAR Part	Part 121
Navigation In Use	other vortac
Flight Phase	cruise : level
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 : 15000 flight time type : 5000
ASRS Report	479861
Person 2
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
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	controller : provided flight assist flight crew : landed in emergency condition flight crew : declared emergency none taken : anomaly accepted
Consequence	other
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

Autoplt engaged, noted main roll trim and rudder trim at abnormal settings from original engagement of autoplt. Prepared for excessive control forces, disengaged autoplt. Aircraft was controled with excessive input forces. Attempted to retrim roll unsuccessfully. (Trim switch later determined to be inoperative for trim down, only worked up.) continued to overpwr aircraft controls while altitude was lost approximately 300 ft -- 11700 ft observed. Climbed back to 12000 ft, advised ATC of control problem (flight control). Eventually used stand-by roll trim, set it to match main roll trim indication. Neutralized forces. Declared emergency. Landed without further incident. No damage, no injuries.

Original NASA ASRS Text

Title: LTT CREW HAD AILERON AND RUDDER TRIM MALFUNCTION IN ZBW CLASS E AIRSPACE.

Narrative: AUTOPLT ENGAGED, NOTED MAIN ROLL TRIM AND RUDDER TRIM AT ABNORMAL SETTINGS FROM ORIGINAL ENGAGEMENT OF AUTOPLT. PREPARED FOR EXCESSIVE CTL FORCES, DISENGAGED AUTOPLT. ACFT WAS CTLED WITH EXCESSIVE INPUT FORCES. ATTEMPTED TO RETRIM ROLL UNSUCCESSFULLY. (TRIM SWITCH LATER DETERMINED TO BE INOP FOR TRIM DOWN, ONLY WORKED UP.) CONTINUED TO OVERPWR ACFT CTLS WHILE ALT WAS LOST APPROX 300 FT -- 11700 FT OBSERVED. CLBED BACK TO 12000 FT, ADVISED ATC OF CTL PROB (FLT CTL). EVENTUALLY USED STAND-BY ROLL TRIM, SET IT TO MATCH MAIN ROLL TRIM INDICATION. NEUTRALIZED FORCES. DECLARED EMER. LANDED WITHOUT FURTHER INCIDENT. NO DAMAGE, NO INJURIES.

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.