SF340 flight crew discovers during climb out that aileron trim operates in the opposite direction fr...

Attributes
ACN	799513
Time
Date	200808
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zzz.artcc
State Reference	US
Environment
Flight Conditions	VMC
Light	Dawn
Aircraft 1
Controlling Facilities	artcc : zzz.artcc
Operator	common carrier : air carrier
Make Model Name	SF 340B
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	799513
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : less severe maintenance problem : improper maintenance
Independent Detector	other flight crewa
Resolutory Action	flight crew : regained aircraft control flight crew : overcame equipment problem
Consequence	other
Factors
Maintenance	performance deficiency : testing
Supplementary
Problem Areas	Aircraft Maintenance Human Performance
Primary Problem	Maintenance Human Performance

Narrative:

During preflight of aircraft X trim test was conducted in accordance with normal procedures. The first officer was the PF. During the late stage of the climb; the first officer made a comment that the aircraft was flying 'strange.' when asked to clarify; he said it seemed out of trim. As we leveled at 11000 ft; the first officer noticed that the main roll trim was operating in an opposite direction commanded. The captain took control of the aircraft and verified the trim malfunction. After the malfunction was verified; the standby roll trim was used and operated normally. The main roll trim was then set to neutral (zero indication); and the standby trim used for the remainder of the flight. After the aircraft was properly trimmed; control of the aircraft was returned to the first officer who acted as PF for the remainder of the flight. No further abnormalities were noted; and the flight landed safely. The trim malfunction was determined in-flight by the first officer acting as PF. Once the malfunction was idented; the faulty trim was isolated and standby trim used for the remainder of the flight. Emergency and abnormal checklists were consulted; and circuit breakers for affected trim were noted. Flight then continued and made a normal landing at ZZZ. The event occurred due to the malfunction of the main roll trim. Callback conversation with reporter revealed the following information: maintenance was performed on the aileron trim system prior to this departure and an error was made in connecting the electrical connections and testing the repair.

Original NASA ASRS Text

Title: SF340 FLT CREW DISCOVERS DURING CLIMB OUT THAT AILERON TRIM OPERATES IN THE OPPOSITE DIRECTION FROM THAT COMMANDED. STANDBY TRIM WAS USED FOR REMAINDER OF FLIGHT.

Narrative: DURING PREFLT OF ACFT X TRIM TEST WAS CONDUCTED IN ACCORDANCE WITH NORMAL PROCS. THE FO WAS THE PF. DURING THE LATE STAGE OF THE CLB; THE FO MADE A COMMENT THAT THE ACFT WAS FLYING 'STRANGE.' WHEN ASKED TO CLARIFY; HE SAID IT SEEMED OUT OF TRIM. AS WE LEVELED AT 11000 FT; THE FO NOTICED THAT THE MAIN ROLL TRIM WAS OPERATING IN AN OPPOSITE DIRECTION COMMANDED. THE CAPT TOOK CTL OF THE ACFT AND VERIFIED THE TRIM MALFUNCTION. AFTER THE MALFUNCTION WAS VERIFIED; THE STANDBY ROLL TRIM WAS USED AND OPERATED NORMALLY. THE MAIN ROLL TRIM WAS THEN SET TO NEUTRAL (ZERO INDICATION); AND THE STANDBY TRIM USED FOR THE REMAINDER OF THE FLT. AFTER THE ACFT WAS PROPERLY TRIMMED; CTL OF THE ACFT WAS RETURNED TO THE FO WHO ACTED AS PF FOR THE REMAINDER OF THE FLT. NO FURTHER ABNORMALITIES WERE NOTED; AND THE FLT LANDED SAFELY. THE TRIM MALFUNCTION WAS DETERMINED INFLT BY THE FO ACTING AS PF. ONCE THE MALFUNCTION WAS IDENTED; THE FAULTY TRIM WAS ISOLATED AND STANDBY TRIM USED FOR THE REMAINDER OF THE FLT. EMER AND ABNORMAL CHKLISTS WERE CONSULTED; AND CIRCUIT BREAKERS FOR AFFECTED TRIM WERE NOTED. FLT THEN CONTINUED AND MADE A NORMAL LNDG AT ZZZ. THE EVENT OCCURRED DUE TO THE MALFUNCTION OF THE MAIN ROLL TRIM. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: MAINTENANCE WAS PERFORMED ON THE AILERON TRIM SYSTEM PRIOR TO THIS DEPARTURE AND AN ERROR WAS MADE IN CONNECTING THE ELECTRICAL CONNECTIONS AND TESTING THE REPAIR.

Data retrieved from NASA's ASRS site as of May 2009 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.

SF340 flight crew discovers during climb out that aileron trim operates in the opposite direction from that commanded. Standby trim was used for remainder of flight.