Narrative:

In level flight at 11000 ft, aircraft rolled left, hesitated, then rapidly continued rolling left. PF disconnected autoplt and recovered manually. During recovery, first officer noticed rudder trim deflected 1/2 scale left and confirmed rudder deflection on icas flight control page. Declared emergency, landed uneventfully. Cockpit communication and communication with approach control was significantly degraded due to continuous autoplt disconnect warning. Could not silence it using 3 autoplt disconnect methods. Did not think of 4TH (ie, turning off data concentrator units). No injuries were reported. Callback conversation with reporter revealed the following information: the PIC stated that aileron trim indicated off center in addition to the rudder deflection. After the disconnect the crew thought that they had a control malfunction and that is why they declared an emergency with ATC. The autoplt does not operate the rudder. After landing maintenance could find nothing wrong. Since there was thought that this incident could have been a wake turbulence encounter, the ATC tapes were pulled as were the flight data recorder tapes. ATC noted a heavy jet in the area but ruled out that as a problem. The aircraft was later successfully test flown and returned to service. Company is still reviewing the flight data recorder. There are 3 basic ways to disconnect the autoplt. One is the trim switch which the captain used, autoplt disconnect switch on unit or the disconnect switch on the glare shield. The operating manual did not list the fourth which would have silenced the alarm, the previously mentioned DCU (data concentrator units) as per maintenance suggestion.

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Original NASA ASRS Text

Title: A CL65 FLC EXPERIENCES A TEMPORARY LOSS OF ACFT CTL AT 11000 FT ON STAR ARR TO CVG. KY.

Narrative: IN LEVEL FLT AT 11000 FT, ACFT ROLLED L, HESITATED, THEN RAPIDLY CONTINUED ROLLING L. PF DISCONNECTED AUTOPLT AND RECOVERED MANUALLY. DURING RECOVERY, FO NOTICED RUDDER TRIM DEFLECTED 1/2 SCALE L AND CONFIRMED RUDDER DEFLECTION ON ICAS FLT CTL PAGE. DECLARED EMER, LANDED UNEVENTFULLY. COCKPIT COM AND COM WITH APCH CTL WAS SIGNIFICANTLY DEGRADED DUE TO CONTINUOUS AUTOPLT DISCONNECT WARNING. COULD NOT SILENCE IT USING 3 AUTOPLT DISCONNECT METHODS. DID NOT THINK OF 4TH (IE, TURNING OFF DATA CONCENTRATOR UNITS). NO INJURIES WERE RPTED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE PIC STATED THAT AILERON TRIM INDICATED OFF CTR IN ADDITION TO THE RUDDER DEFLECTION. AFTER THE DISCONNECT THE CREW THOUGHT THAT THEY HAD A CTL MALFUNCTION AND THAT IS WHY THEY DECLARED AN EMER WITH ATC. THE AUTOPLT DOES NOT OPERATE THE RUDDER. AFTER LNDG MAINT COULD FIND NOTHING WRONG. SINCE THERE WAS THOUGHT THAT THIS INCIDENT COULD HAVE BEEN A WAKE TURB ENCOUNTER, THE ATC TAPES WERE PULLED AS WERE THE FLT DATA RECORDER TAPES. ATC NOTED A HVY JET IN THE AREA BUT RULED OUT THAT AS A PROB. THE ACFT WAS LATER SUCCESSFULLY TEST FLOWN AND RETURNED TO SVC. COMPANY IS STILL REVIEWING THE FLT DATA RECORDER. THERE ARE 3 BASIC WAYS TO DISCONNECT THE AUTOPLT. ONE IS THE TRIM SWITCH WHICH THE CAPT USED, AUTOPLT DISCONNECT SWITCH ON UNIT OR THE DISCONNECT SWITCH ON THE GLARE SHIELD. THE OPERATING MANUAL DID NOT LIST THE FOURTH WHICH WOULD HAVE SILENCED THE ALARM, THE PREVIOUSLY MENTIONED DCU (DATA CONCENTRATOR UNITS) AS PER MAINT SUGGESTION.

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.