Narrative:

After leveling at FL410 for 15 minutes (2 hours into flight) the pfd aileron mistrim indicator started to indicate yellow then red in both directions. The aircraft started to oscillate in roll from the left to the right with 15 degrees of bank each time. We disconnected the autopilot and noted that extreme control inputs to the ailerons were required to control the airplane. With about 20-30 pounds of control force we were able to only affect the bank by about 1-2 degrees. We applied both left and right aileron trim; first small amounts then full trim. Even with full right or left trim the aircraft did not bank. We requested a lower altitude with center. We consulted the emergency checklist for jammed roll. As we were still in control of the aircraft and able to maintain straight and level flight we elected not to pull the roll handle and separate the controls. As we descended we called dispatch and discussed the symptoms. We were advised that this has happened to this tail number before. As we descended to a lower altitude we started to gain control of the ailerons. At FL350 we had full control of the ailerons and were able to re engage the autopilot. We continued to our destination. Sat -62 fuel 4;000 and balanced. The aircraft sat out in the rain the night before. As this is a repeat write-up on this plane I feel it is important to do extensive test flights with this aircraft to make sure this problem is corrected before it is released to the line again. I also think; even though the problem was corrected at FL350; that we should have left rvsm airspace sooner than we did.

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Original NASA ASRS Text

Title: G200 flight crew experienced jammed ailerons at FL410. Roll control was possible and the crew elected to descend to warmer air where the controls return to normal.

Narrative: After leveling at FL410 for 15 minutes (2 hours into flight) the PFD aileron mistrim indicator started to indicate yellow then red in both directions. The aircraft started to oscillate in roll from the left to the right with 15 degrees of bank each time. We disconnected the autopilot and noted that extreme control inputs to the ailerons were required to control the airplane. With about 20-30 LBS of control force we were able to only affect the bank by about 1-2 degrees. We applied both left and right aileron trim; first small amounts then full trim. Even with full right or left trim the aircraft did not bank. We requested a lower altitude with center. We consulted the emergency checklist for jammed roll. As we were still in control of the aircraft and able to maintain straight and level flight we elected not to pull the roll handle and separate the controls. As we descended we called dispatch and discussed the symptoms. We were advised that this has happened to this tail number before. As we descended to a lower altitude we started to gain control of the ailerons. At FL350 we had full control of the ailerons and were able to re engage the autopilot. We continued to our destination. SAT -62 Fuel 4;000 and balanced. The aircraft sat out in the rain the night before. As this is a repeat write-up on this plane I feel it is important to do extensive test flights with this aircraft to make sure this problem is corrected before it is released to the line again. I also think; even though the problem was corrected at FL350; that we should have left RVSM airspace sooner than we did.

Data retrieved from NASA's ASRS site as of April 2012 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.