Narrative:

Departing monterey, ca, (going to phx) climbed out through FL200. We were alerted of an autoplt pitch trim and then an autoplt pitch trim nose down malfunction (master caution annunciation). We followed CRM procedures which were pretty vague, told us to disconnect the autoplt and expect to use pressure or maintain pressure on the yoke, which we had to maintain about 2 inches or about 30-40 pounds of forward pressure to maintain our altitude of FL230. And while hand flying the aircraft, I noticed that we could trim the nose up but not down past 4 units of trim. We engaged the autoplt again to see if it would help us maintain level flight, and it did. We called maintenance over frequency and they were absolutely no help at all -- had no suggestions or anything helpful to try. So then we talked to dispatch and told them we were diverting to fresno, approximately 20 mins from where we were. We declared an emergency and came in and landed uneventfully. Maintenance tried running a test on the computer unsuccessfully and tried resetting it -- no joy. They put a new computer in and it worked momentarily, the broke/jammed again. Maintenance said the next day they replaced the stabilizer trim actuator and motor and when they got the motor out said something was loose inside. Also was informed the NTSB was going to be involved since it was a flight control problem. Also, this is similar to the problem with the MD80's and their stabilizer trim.

Related reports:

Google
 

Original NASA ASRS Text

Title: A CANADAIR CL65 CLBING AT FL200 HAS AUTOPLT AND MAIN ELECTRIC TRIM SYS FAIL NOSE UP CAUSED BY AN INOP STABILIZER ACTUATOR AND MOTOR.

Narrative: DEPARTING MONTEREY, CA, (GOING TO PHX) CLBED OUT THROUGH FL200. WE WERE ALERTED OF AN AUTOPLT PITCH TRIM AND THEN AN AUTOPLT PITCH TRIM NOSE DOWN MALFUNCTION (MASTER CAUTION ANNUNCIATION). WE FOLLOWED CRM PROCS WHICH WERE PRETTY VAGUE, TOLD US TO DISCONNECT THE AUTOPLT AND EXPECT TO USE PRESSURE OR MAINTAIN PRESSURE ON THE YOKE, WHICH WE HAD TO MAINTAIN ABOUT 2 INCHES OR ABOUT 30-40 LBS OF FORWARD PRESSURE TO MAINTAIN OUR ALT OF FL230. AND WHILE HAND FLYING THE ACFT, I NOTICED THAT WE COULD TRIM THE NOSE UP BUT NOT DOWN PAST 4 UNITS OF TRIM. WE ENGAGED THE AUTOPLT AGAIN TO SEE IF IT WOULD HELP US MAINTAIN LEVEL FLT, AND IT DID. WE CALLED MAINT OVER FREQ AND THEY WERE ABSOLUTELY NO HELP AT ALL -- HAD NO SUGGESTIONS OR ANYTHING HELPFUL TO TRY. SO THEN WE TALKED TO DISPATCH AND TOLD THEM WE WERE DIVERTING TO FRESNO, APPROX 20 MINS FROM WHERE WE WERE. WE DECLARED AN EMER AND CAME IN AND LANDED UNEVENTFULLY. MAINT TRIED RUNNING A TEST ON THE COMPUTER UNSUCCESSFULLY AND TRIED RESETTING IT -- NO JOY. THEY PUT A NEW COMPUTER IN AND IT WORKED MOMENTARILY, THE BROKE/JAMMED AGAIN. MAINT SAID THE NEXT DAY THEY REPLACED THE STABILIZER TRIM ACTUATOR AND MOTOR AND WHEN THEY GOT THE MOTOR OUT SAID SOMETHING WAS LOOSE INSIDE. ALSO WAS INFORMED THE NTSB WAS GOING TO BE INVOLVED SINCE IT WAS A FLT CTL PROB. ALSO, THIS IS SIMILAR TO THE PROB WITH THE MD80'S AND THEIR STABILIZER TRIM.

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.