CE560XL citation flight crew has a 'stabilizer mistrim comparison' and 'autoplt pitch mistrim' light...

Attributes
ACN	691996
Time
Date	200603
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : rno.airport
State Reference	NV
Altitude	msl single value : 14500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : rno.tracon
Operator	general aviation : corporate
Make Model Name	Citation Excel
Operating Under FAR Part	Part 91
Flight Phase	climbout : takeoff climbout : initial
Route In Use	departure sid : mustang6
Flight Plan	IFR
Person 1
Affiliation	company : corporate
Function	flight crew : first officer
Qualification	pilot : atp pilot : cfi pilot : multi engine
Experience	flight time last 90 days : 150 flight time total : 3631 flight time type : 70
ASRS Report	691996
Person 2
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : less severe
Independent Detector	other flight crewa other flight crewb
Resolutory Action	aircraft : equipment problem dissipated flight crew : landed as precaution flight crew : overcame equipment problem
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

Upon climb out from rno on the MUSTANG6 departure; passing through 14500 ft; we had a 'stabilizer mis-comparison' and 'autoplt pitch mis-trim' master caution lights illuminate and then extinguish. The autoplt was flying the aircraft. When the lights illuminated; I looked over at the aircraft pitch trim indicator and saw that the aircraft was trimmed full nose down. I disconnected the autoplt and told the PIC that I was getting a vibration in the control column. The PIC then ran the 'stabilizer mis-comparison' emergency checklist. One step in the checklist states to reduce speed to below 200 KTS. The aircraft was indicating approximately 230 KTS at this point. As I slowed the aircraft below 200 KTS; the 'stabilizer mis-comparison' light flashed on and off and the aircraft started pitching down. It took full aft yoke to arrest the descent. I informed the PIC that I was having difficulty controling the aircraft and that we needed to declare an emergency and return to rno immediately. After several seconds; I was able to retrim the aircraft to level flight. The PIC then contacted one of our chief pilots via the aircraft flight phone and let him know that we were returning to rno and that we intended to do a no-flap landing as we did not want to change the confign of the aircraft. During this time; I informed the PIC that the controls felt 'mushy' and I agreed that a no-flap landing was the best course of action. We landed uneventfully and upon inspecting the aircraft after landing; we noticed no damage and nothing out of the ordinary. Callback conversation with reporter revealed the following information: reporter indicated that they performed the QRH checklist procedures and the trim and autoplt malfunction was cleared. However; he indicated that there appeared to be a vibration and that the flight crew elected to not change the confign of the aircraft and to perform a 'no flap' landing back at their departure airport. Postflt investigation revealed no problems with the aircraft. Reporter indicated that they were not sure if there was anything wrong with the aircraft.

Original NASA ASRS Text

Title: CE560XL CITATION FLT CREW HAS A 'STABILIZER MISTRIM COMPARISON' AND 'AUTOPLT PITCH MISTRIM' LIGHTS ALONG WITH A 'MASTER CAUTION' LIGHT. FLT CREW PERFORMS THE EMER PROCS AND RETURNS TO LAND.

Narrative: UPON CLBOUT FROM RNO ON THE MUSTANG6 DEP; PASSING THROUGH 14500 FT; WE HAD A 'STABILIZER MIS-COMPARISON' AND 'AUTOPLT PITCH MIS-TRIM' MASTER CAUTION LIGHTS ILLUMINATE AND THEN EXTINGUISH. THE AUTOPLT WAS FLYING THE ACFT. WHEN THE LIGHTS ILLUMINATED; I LOOKED OVER AT THE ACFT PITCH TRIM INDICATOR AND SAW THAT THE ACFT WAS TRIMMED FULL NOSE DOWN. I DISCONNECTED THE AUTOPLT AND TOLD THE PIC THAT I WAS GETTING A VIBRATION IN THE CTL COLUMN. THE PIC THEN RAN THE 'STABILIZER MIS-COMPARISON' EMER CHKLIST. ONE STEP IN THE CHKLIST STATES TO REDUCE SPD TO BELOW 200 KTS. THE ACFT WAS INDICATING APPROX 230 KTS AT THIS POINT. AS I SLOWED THE ACFT BELOW 200 KTS; THE 'STABILIZER MIS-COMPARISON' LIGHT FLASHED ON AND OFF AND THE ACFT STARTED PITCHING DOWN. IT TOOK FULL AFT YOKE TO ARREST THE DSCNT. I INFORMED THE PIC THAT I WAS HAVING DIFFICULTY CTLING THE ACFT AND THAT WE NEEDED TO DECLARE AN EMER AND RETURN TO RNO IMMEDIATELY. AFTER SEVERAL SECONDS; I WAS ABLE TO RETRIM THE ACFT TO LEVEL FLT. THE PIC THEN CONTACTED ONE OF OUR CHIEF PLTS VIA THE ACFT FLT PHONE AND LET HIM KNOW THAT WE WERE RETURNING TO RNO AND THAT WE INTENDED TO DO A NO-FLAP LNDG AS WE DID NOT WANT TO CHANGE THE CONFIGN OF THE ACFT. DURING THIS TIME; I INFORMED THE PIC THAT THE CTLS FELT 'MUSHY' AND I AGREED THAT A NO-FLAP LNDG WAS THE BEST COURSE OF ACTION. WE LANDED UNEVENTFULLY AND UPON INSPECTING THE ACFT AFTER LNDG; WE NOTICED NO DAMAGE AND NOTHING OUT OF THE ORDINARY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR INDICATED THAT THEY PERFORMED THE QRH CHKLIST PROCS AND THE TRIM AND AUTOPLT MALFUNCTION WAS CLRED. HOWEVER; HE INDICATED THAT THERE APPEARED TO BE A VIBRATION AND THAT THE FLT CREW ELECTED TO NOT CHANGE THE CONFIGN OF THE ACFT AND TO PERFORM A 'NO FLAP' LNDG BACK AT THEIR DEP ARPT. POSTFLT INVESTIGATION REVEALED NO PROBS WITH THE ACFT. RPTR INDICATED THAT THEY WERE NOT SURE IF THERE WAS ANYTHING WRONG WITH THE ACFT.

Data retrieved from NASA's ASRS site as of January 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.

CE560XL citation flight crew has a 'stabilizer mistrim comparison' and 'autoplt pitch mistrim' lights along with a 'master caution' light. Flight crew performs the emergency procedures and returns to land.