Date: 201911
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: PC-12
Operator: Air Taxi
Operating under: Part 135
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
ATC / advisory: TRACON ZZZ
Aircraft component: Fuel System
Component problem: Malfunctioning
Reporter organization: Air Taxi
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Workload; Troubleshooting; Time Pressure
Anomaly: Aircraft Equipment Problem Critical; Inflight Event / Encounter Fuel Issue
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Landed in Emergency Condition
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Revenue leg with X passengers. Second in Command was Pilot Flying; I was Pilot Monitoring. Upon reaching 16;500 feet I determined the cruise power setting; and we ran the cruise checklist. The fuel was balanced and normal; neither myself nor the Second in Command recall seeing an unusual imbalance or a fuel pump light on. Once the checklist was complete; I touched base with the passengers. We were approximately 40 minutes from our destination at this time and talking to Center. As I reached down to grab the can to start paperwork; I noticed that both fuel pumps were illuminated. I noticed them both turn on; turn off; then immediately turn back on. This gave me cause for concern as the only condition that would have both pumps on in-flight suggest low fuel pressure. I pointed this to the Second in Command and began running the checklist.I first went to the fuel pumps page; which stated 'Condition: Left Fuel Pump is operating. If indication cycles on and off every 10 seconds: Carry out Low Fuel Pressure Emergency Checklist'. I ran the checklist; which called for a reduction in power and to turn the fuel pumps on. I instructed the Second in Command to set approximately 15 psi torque; which he did. The checklist next called for a monitor of the balance. At this time neither the Second in Command or myself noticed an imbalance; so we continued with the pumps on. The checklist calls for a descent to warmer air; as ice crystals may cause the fuel filter to be blocked. I made a gut decision that ice was unlikely to be the culprit; as the outside air temperature was +6 and we had only just leveled off at the coldest temperature we had encountered. The next step of the checklist called for the pumps to be returned to auto. I did this and noticed the pump lights remained illuminated and continued to cycle. I returned the switches to ON and reached the end of the checklist which called for an immediate landing.I notified Center; stated we would be diverting to a nearer report and squawked XXXX. The Second in Command and I performed the descent and approach checklists concurrently. I then briefed the passengers that we had a mechanical issue and were going to make a precautionary landing. I guided the Second in Command to stay high on the approach to guarantee a landing in the event of an engine failure; and once a landing was assured we put the gear and flaps out to bleed energy and increase our rate of descent. The before landing checklist was completed and the landing was nominal. Upon shutdown I noted that there was a 4 or 5 segment fuel tank imbalance; right tank heavy. The fuel filter bypass was in its normal shut position; indicating fuel had been passing through the filter normally for the flight.I genuinely feel the Second in Command and myself handled the situation as safely as possible given the circumstances. There was no rushing; no skipped items; clear and concise cockpit communication; strict adherence to Standard Operating Procedures; good airmanship; and excellent teamwork. This event highlights the strengths of the training department.




Synopsis: PC12 Captain reported a fuel system malfunction during cruise resulting in a diversion.