Small aircraft has problem with trim control causing altitude deviation.

Attributes
ACN	261380
Time
Date	199401
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : ecb
State Reference	KY
Altitude	msl bound lower : 7000 msl bound upper : 7600
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Bonanza 36
Operating Under FAR Part	Part 91
Flight Phase	cruise other
Route In Use	enroute airway : zid
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private pilot : instrument
Experience	flight time last 90 days : 60 flight time total : 509 flight time type : 60
ASRS Report	261380
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : overshoot non adherence : clearance
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course none taken : unable
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation other

Narrative:

On my climb out from mt sterling, ky, the A36 trimmed up ok but had some difficulty getting trim down. My assigned altitude was 5000 ft. I was in the middle of a broken cloud cover so I requested 7000 ft. ZID cleared me to 7000. The plane was in a pitch up confign. Upon reaching 7000 ft, I pushed the nose over and was trying to trim down. I was VFR on top at 7000 ft. As I was working with the trim, center called and asked what my assigned altitude was. I said 7000 ft. I pushed the nose back over to get to 7000 ft and turned the autoplt altitude hold at 7000 ft, that worked. Center then asked what my condition was. I noticed I was at 7600 ft, which I reported as such. Center asked what my assigned altitude was, I reported VFR on top. I did not report the trim problem. As I started my ILS into crw and turned off the autoplt the plane went to a trim up position. On the ground, the trim was free. The return flight to iob had the same problem. The outside air temperature was minus 20 degrees F at 7000 ft. I will write back with cause.

Original NASA ASRS Text

Title: SMA HAS PROB WITH TRIM CTL CAUSING ALTDEV.

Narrative: ON MY CLBOUT FROM MT STERLING, KY, THE A36 TRIMMED UP OK BUT HAD SOME DIFFICULTY GETTING TRIM DOWN. MY ASSIGNED ALT WAS 5000 FT. I WAS IN THE MIDDLE OF A BROKEN CLOUD COVER SO I REQUESTED 7000 FT. ZID CLRED ME TO 7000. THE PLANE WAS IN A PITCH UP CONFIGN. UPON REACHING 7000 FT, I PUSHED THE NOSE OVER AND WAS TRYING TO TRIM DOWN. I WAS VFR ON TOP AT 7000 FT. AS I WAS WORKING WITH THE TRIM, CTR CALLED AND ASKED WHAT MY ASSIGNED ALT WAS. I SAID 7000 FT. I PUSHED THE NOSE BACK OVER TO GET TO 7000 FT AND TURNED THE AUTOPLT ALT HOLD AT 7000 FT, THAT WORKED. CTR THEN ASKED WHAT MY CONDITION WAS. I NOTICED I WAS AT 7600 FT, WHICH I RPTED AS SUCH. CTR ASKED WHAT MY ASSIGNED ALT WAS, I RPTED VFR ON TOP. I DID NOT RPT THE TRIM PROB. AS I STARTED MY ILS INTO CRW AND TURNED OFF THE AUTOPLT THE PLANE WENT TO A TRIM UP POS. ON THE GND, THE TRIM WAS FREE. THE RETURN FLT TO IOB HAD THE SAME PROB. THE OUTSIDE AIR TEMP WAS MINUS 20 DEGS F AT 7000 FT. I WILL WRITE BACK WITH CAUSE.

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.