Date: 202103
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: PC-12
Operator: Personal
Operating under: Part 91
Flight plan: IFR
Mission: Personal
Flight phase: Initial Approach
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Indicating and Warning - Fuel System
Component problem: Malfunctioning
Reporter organization: Personal
Reporter function: Pilot Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Private
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Weight And Balance; Inflight Event / Encounter Fuel Issue
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition; Flight Crew Diverted
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: We had been flying on an IFR flight plan with a destination of ZZZ; a non-towered airport just north of ZZZ1.  As usual; we canceled IFR once we got close to the airport; and began our VFR approach to Runway 24.  Upon approach into ZZZ; got a 'Fuel Imbalance' CAS (Crew Alerting System) message with 5 'segments' of difference; without noticing any prior indication of an issue. While dealing with this issue; we also had to deal with other nearby aircraft targets as well (in the practice area right near the traffic pattern for ZZZ; no doubt).  Per the appropriate checklist; we took the action of turning on the fuel pump on the fuller side. In spite of taking this action; the indication of the problem got markedly worse (increased to 6 and then to 7 segments) within only 2-3 minutes; yet we still had no controllability issues. We then ended up getting a 'Fuel Balance Fault' CAS message as well.  In sum; we were close to the ground; in the vicinity of Class B; near a practice area; trying to deal with this issue. We elected to focus primarily on doing the most important things: aviate; navigate; and communicate.  We flew the airplane and began a diversion towards ZZZ1; which we could clearly see.  It has a longer and wider runway; which would be important in landing a bit faster than normal to avoid potential controllability issues; and it also has emergency equipment available as well. Notified ATC since the issue had happened so quickly; and the fuel monitoring device depicted that the problem had gotten markedly worse so quickly as well -- felt it best to get on the ground quickly before a controllability issue developed.  Landed without incident. If we hadn't been so close to landing (instead being enroute at altitude in the middle of nowhere); we could have obviously spent more time analyzing and dealing with the issue in flight.  After landing and thinking about it a bit; we believed it was an indication problem; and not an actual fuel imbalance after all.  Upon further reflection overnight of our actions during the flight; we concluded that we wouldn't do anything different than we did.  In general; we were pleased with what we did.  It was a particularly busy time with the nearby traffic; and we quickly focused on the most important things of aviate; navigate; and communicate.  The notifying ATC might be questioned; but only with hindsight; I believe -- I am comfortable with this judgment call.




Synopsis: PC-12 pilot reported a fuel imbalance inflight.