C525 captain reported uncommanded roll issues associated with a jammed atlas active winglet system.

Narrative:

I experienced uncommanded roll of the aircraft during climbout [at 3;000 feet AGL]. Had critical control problems that required my full attention to keep the aircraft from rolling over. Required full left aileron and full right rudder and aileron trim to keep the aircraft in a level flight attitude. Was in contact with ZZZ center a few minutes after this happened. ZZZ center handed me off to ZZZ1 center. As I recall I communicated that I was having aircraft control problems; but at the time did not indicate the severity of the problem. I could not engage the a/P (autopilot). Felt I had to get to a higher altitude. I accepted a climb clearance to FL260. I had difficulty leveling off and overshot by 500 feet. It also took me a few minutes to correct down to FL260; since I was continuing to experience aircraft control issues. I was busy trying to troubleshoot the problem all during this time. At no time could I remove my hand from the control yoke; until leveling off at cruise altitude when I was able to re-engage the a/P. The control issues were attributed to a malfunction of the tamarack winglet system.the left tacs control surface was jammed in the full down position and the right tacs was in a neutral position. Remained so for the remainder of the flight. Tried to do an emergency reset of the system in flight; but was unable to reset the winglet system. Decided to burn fuel to lighten the aircraft and divert.

Original NASA ASRS Text

Title: C525 Captain reported uncommanded roll issues associated with a jammed ATLAS Active Winglet system.

Narrative: I experienced uncommanded roll of the aircraft during climbout [at 3;000 feet AGL]. Had critical control problems that required my full attention to keep the aircraft from rolling over. Required full left aileron and full right rudder and aileron trim to keep the aircraft in a level flight attitude. Was in contact with ZZZ Center a few minutes after this happened. ZZZ Center handed me off to ZZZ1 Center. As I recall I communicated that I was having aircraft control problems; but at the time did not indicate the severity of the problem. I could not engage the A/P (autopilot). Felt I had to get to a higher altitude. I accepted a climb clearance to FL260. I had difficulty leveling off and overshot by 500 feet. It also took me a few minutes to correct down to FL260; since I was continuing to experience aircraft control issues. I was busy trying to troubleshoot the problem all during this time. At no time could I remove my hand from the control yoke; until leveling off at cruise altitude when I was able to re-engage the A/P. The control issues were attributed to a malfunction of the Tamarack Winglet System.The left TACS control surface was jammed in the full down position and the right TACS was in a neutral position. Remained so for the remainder of the flight. Tried to do an emergency reset of the system in flight; but was unable to reset the winglet system. Decided to burn fuel to lighten the aircraft and divert.

Data retrieved from NASA's ASRS site 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.

Attributes
ACN	1638883
Time
Date	201904
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Aircraft 1
Make Model Name	Citationjet (C525/C526) - CJ I / II / III / IV
Operating Under FAR Part	Part 91
Flight Phase	Climb
Route In Use	Direct
Flight Plan	IFR
Component
Aircraft Component	Aeroplane Flight Control
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Multiengine Flight Crew Flight Instructor Flight Crew Instrument
Experience	Flight Crew Last 90 Days 40 Flight Crew Total 15600 Flight Crew Type 4000
Events
Anomaly	Aircraft Equipment Problem Critical Inflight Event / Encounter Loss Of Aircraft Control