Date: 201910
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: Medium Transport; Low Wing; 2 Turbojet Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Flap/Slat Control System
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Human factors: Workload; Troubleshooting; Time Pressure; Distraction; Situational Awareness
Second reporter function: Captain; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Less Severe; Inflight Event / Encounter Fuel Issue; Inflight Event / Encounter Weather / Turbulence
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Diverted; Flight Crew Landed in Emergency Condition; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Overcame Equipment Problem
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: During descent to FL230; EICAS messages SPS ADVANCED and FLAP LOW SPEED illuminated. As PM (Pilot Monitoring) I executed the appropriate QRH checklist for both messages and noted the effect would require additional time for flap extension during the approach. Flap handle was zero and no configuration changes had been made at that time. After descending below 10;000 ft.; estimated around 7;000 ft. and approximately 210 kts.; I elected to select Flaps 9 to evaluate the condition of the flap system at that point. The flaps extended at half speed to 4 degrees; and then the EICAS presented FLAP FAIL. The indication for flaps went amber with a dash in the box. At this point we advised ATC we would require additional time to run checklists and evaluate our situation. ATC responded that without status escalation they could not offer us additional consideration. At that time I elected to [request priority handling]; and reported souls on board and fuel state. At this point I elected to fly the aircraft while the First Officer executed the QRH FLAP FAIL checklist. ATIS reported conditions for ZZZ Runway XXL at that time included rain; so performance calculations for a wet runway with RCC (Runway Condition Code) of 5 and QRH malfunction correction factor in the FMS indicated that the runway would be too short by several thousand ft. FMS indicated 8;207 available with an excess of 11;000 required. We then took a quick moment to consider alternate airport options. We reported the situation to Dispatch via ACARS. After checking ATIS weather and runway lengths at ZZZ1 I made the command decision to divert to ZZZ1. Runway length and contamination were considered [and] the runway performance confirmed in the FMS. Later during vectors for the approach to Runway XYR at ZZZ1; Dispatch did suggest diverting to ZZZ2; which had a maintenance facility I was previously unaware of; but at that point fuel state was 3;000 lbs. and I believed it to be safer to proceed to ZZZ1 at that point. Upon reaching ZZZ1; we landed on Runway XYR at the required speeds per the QRH without difficulty. I had previously requested CFR (Crash Fire Rescue) on standby and once clear of the runway; told ATC to stand down CFR. We requested a place to sit on a taxiway while we coordinated for a gate to deplane the passengers. We were sent to Gate XXX; operated by [other Company] personnel. We parked; shut down the aircraft and deplaned the passengers. No aircraft damage beyond the stated malfunction occurred and no crew or passenger injuries were sustained. After shutdown I contacted the Company. The flight concluded without further incident. [I suggest] additional non-filed diversionary planning training/data available for pilots and dispatchers.


Second narrative: In the absence of required alternate airports; options for diversion are left almost entirely to the knowledge and imagination of the flight crew. A list of potential diversion or alternate airports; facilities available; etc.; in the informational sections of Jeppesen charts or the release could be beneficial. My decision to divert to ZZZ1 was largely required by performance requirements; but my knowledge of ZZZ1 as a facility comes from experience prior to my time at [the current Company]. A less familiar flight crew may not have the same well of experience to draw from. Other than as a reporting point; Dispatch did little to alleviate the situation and information offered was incomplete or required additional information to be used for decision making. ZZZ2 was offered as a potential alternate without weather or fuel requirement data and as such I could not consider it at that time. Had it been offered earlier into the event; that may have differed. In this scenario; Dispatch was not so much [of] an asset [but more] as an additional task to be completed. [I] suggest additional training or alternate designations on releases to augment the diversion decision making process in the future.


Synopsis: Corporate jet flight crew reported a flap malfunction resulting in diverting to an alternate airport.