Date: 201509
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight phase: Parked
Aircraft component: Fuel Crossfeed
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness; Troubleshooting
Anomaly: Aircraft Equipment Problem Less Severe; Inflight Event / Encounter Fuel Issue
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Flight Crew Landed As Precaution; Flight Crew Diverted; Flight Crew Overcame Equipment Problem; General Maintenance Action
Contributing factors: Manuals; Aircraft; Procedure
Primary problem: Aircraft

Narrative: AC was fueled incorrectly (Ramp=10774lbs.). Fuel was loaded Left wing ~ +3800/Center ~ +3300/Right ~ +3800. During Eng. Start Chk.; noted the Center fuel load; O/S (outside) OM Limitation. Notified/concurred with Dispatcher; it was decided to have fuel taken from center tank (1200 lbs); then redistributed to Wings (600 lbs each); thus bringing fuel load in compliance with  OM Limitations. Coordinated thru Ops; fueling supervisor came/oversaw process. She chided her fueler(s) for improperly following Fuel Procedures (FO was o/s ensuring they understood what needed to happen re: lbs. of fuel; etc.). Remainder of checklists run normally; taxied out; and departed.In route; noted Right Fuel Pump on; in assoc. with X-Flow Pump for auto fuel transfer; still had fuel in Center Tank; Right Wing Tank being fed (per Fuel Synoptic). At TOC; noted FOB at 9020lbs vs Release = 9024lbs. Fuel transfer still taking place. Over ZZZ1; checked fuel vs. Release; and was within +/-50lbs. Did note/discuss with FO the fuel imbalance was increasing between L and R wing tanks. Shortly thereafter; received Amber Fuel Imbalance Caution Message (imbalance ~800lbs). Ran the QRH for Message. Note: at some point in this; we had advised Dispatcher via ACARS of potential fuel imbalance problem. We did not feel we had a leak because our fuel checks were nearly matched to the Release values. Fuel synoptic showed fuel transferring to Right Wing Tank; but imbalance remained. Per QRH; had FA do visual check on Right Wing with inspection lights on. She reported nothing visibly leaking. We initiated Gravity Feed and coordinated with Center to make right 360* turns in hopes of transferring fuel; Center Tank was empty at this time. Imbalance persisted; and finally got to approximately 1200lbs between the Wing Tanks (Right Wing approximately 1200lbs less than Left Wing per QRH (Fuel synoptic showed Amber quantities).Continued coordinating with Dispatcher re: diversion. Was agreed upon to go to ZZZ2. Continued any remaining QRH procedures. Advised Center; proceeded direct to ZZZ2. Planned for an ILS approach. Arrived over ZZZ2 +FL240 (had requested to stay high...in case of a flameout). Coordinated with ATC & Approach Control of our intention to descend via a wide; RIGHT hand turn; thus hoping to eliminate / decrease the imbalance. This did have the desired effect. Imbalance began a slow; steady decrease. Turned a base leg at 2500 ft MSL; clean; airspeed decreasing from <250 kts. Joined final approx. 6-10 miles out; clean; slowing to 180 kts. Began a normal configuration for landing once we felt Aircraft was handling normally. Landed; stopped on Runway.Had decided (all crew members in loop) to remain on RWY while Fire/Rescue (F/R) inspected A/C for any leaking fuel. In communication with all parties on Tower frequency. Passengers were advised to remain seated; follow any FA instructions. Fire/Rescue advised no leaking fuel. A/C then taxied to non-gate parking spot; escorted by F/R. Normal shut-down. Requested/discussed F/R would inspect A/C again once parked. Advised FA not to open door until we had received an 'All Clear' from F/R; seat belt sign still ON. Once 'All Clear' received; turned off seatbelt sign; advised FA to open main cabin door. Normal passenger deplanement. Normal post-flight shutdown; etc. Fuel quantities at this time were: L=3080lbs/C=0 lbs/R= 3090lbs. Imbalance had corrected itself. Then contacted Maintenance Control (detailed discussion); contacted Dispatch; called/left message for chief pilot on call per name/number provided by dispatcher. As a result of either a Fuel Control/Fuel Computer Logic problem (this item was replaced by Maintenance next morning in ZZZ2); or possibly a stuck/inoperative valve (possibility as explained to me by Maintenance Control during my post-event extended phone conversation; the AC ended up with a large fuel imbalance.)Procedures in QRH 'helped'; but did not resolve problem. PF & PM attempted to remedy situation; all the while planning for a possible divert. Largest 'threat' was the QRH leading us to believe we may have had a fuel leak; but as explained our Fuel Check Point Numbers were nearly spot-on. AC fuel imbalance continued.I believe crew did a fantastic job. It's not uncommon to see a powered cross flow initiated as a result of making several same direction turns (as was the case on climb out). However; this event showed that even though the system is doing its job; it may be unable to keep up. We were fortunate in that we did see it & were monitoring; ironically; I (PF) had just mentioned to PM that if the balance differential went any further; we'd see an Amber FUEL IMBALANCE Caution--which happened fairly shortly after that. Only thing that may assist crews--our case in particular-- would be a change to the QRH (our procedures we ran) that; via a rhombus step (Yes / No format) ; if you are 'sure' you are NOT leaking fuel; then do a side-slip maneuver to try to alleviate the imbalance. That step/procedure was not in our QRH flow.




Synopsis: CRJ200 Captain experienced a fuel imbalance that gradually developed during climbout and cruise. The only remedy was to turn off the fuel pumps; open the cross feed; and slip the aircraft. The crew elected to divert and landed with the fuel in balance.