Date: 202102
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Dawn
Aircraft: B737 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Oil Indicating System
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Anomaly: Aircraft Equipment Problem Critical
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Inflight Shutdown; Flight Crew Landed in Emergency Condition; Flight Crew Took Evasive Action; Flight Crew Diverted; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Aircraft X departing from ZZZ bound for ZZZ1 scheduled to depart at XA:45. My FO (First Officer) and I both discussed the hydraulic maintenance write ups from the previous day and saw no obvious irregularities. All ground activities were normal; I.e. engine start and taxi. FO was the pilot flying; I was the pilot monitoring. Climb to our cruise altitude of FL380 was uneventful. Approximately 40 minutes into flight we got the B system engine low pressure light; we used the QRH procedures for this malfunction which resulted in the switch being turned off. We checked the system page and saw that our fluid quantity was rising and stabilized at 106% and pressure was at approximately 2700 psi. The #2 oil filter bypass light came on; we again used the QRH which had us reduce thrust on the #2 engine to see if the light would extinguish. After moving the throttle to idle the light was still illuminated which; as per the checklist; required us to shut down the engine. Immediately prior to shutting down the engine I contacted Purser with our plan to secure the engine; our ETA to ZZZ1; and state that no cabin prep would be necessary. He told us that a deadheading pilot was onboard so we asked that he send him forward to the cockpit. Upon completion of the Engine Failure or Shutdown Checklist we advised ATC; got a more direct turn to ZZZ1; and descended to FL240. Once established at FL240 we saw that our closest divert airport was ZZZ2; we requested and received ATC clearance direct to the field. Our decision to proceed to ZZZ2 vs. ZZZ1 was passed on to Purser. We tried initially to contact Dispatch by sending a 'Call me' message from the ACARS. It took quite a while to get a response containing a frequency and I think the actual first response we got from Dispatch was that they had noticed that we had descended and wondered if we were having an issue. We did confirm that we had shut down an engine and once a decision had been made to go to ZZZ2 we confirmed that with Dispatch through ACARS messaging. We had good communication with Center but were never able to speak to Dispatch; though as we got close to ZZZ2 we did hear ZZZ3 ARINC; though they could never hear us. At about the same time Center notified us that our company was trying to contact us on the frequency that we had previously been given; we told them that they could not hear us so they relayed our final intentions to the company. I can only assume that our altitude might have played a role in this poor communication with Dispatch; though we had no issues with ATC. In the approximately 45 minutes of cruise prior to descent into ZZZ2; we discussed steps taken; checklist to be completed (One Engine Inoperative Landing Checklist) and other considerations. As a result; I switched pilot flying and pilot monitoring duties. At approximately 60 miles from ZZZ2 we commenced our descent. With all checklists complete and planning for a flaps 15 approach to the ILS at ZZZ2; we were given an intercept heading and selected flaps 15 for landing. The flaps did not move; so we requested vectors across final while we troubleshot the flaps. At this time I assumed the duties of flying the aircraft and talking to ATC. [The other two pilots] took on the task of determining why the flaps did not extend. Shortly after; we checked our system page and discovered that we had zero B System hydraulic quantity; I do not recall the B system pressure. We decided to run the Loss of System B checklist which led us to electrically extend the flaps. After one more series of turns to intercept final; we fully configured and executed an uneventful approach and landing at ZZZ2. After being inspected by Fire and Rescue Crews we taxied to our gate.




Synopsis: Captain reported loss of System B engine driven hydraulic pump and the number 2 engine filter bypass light illuminating resulted in an inflight shutdown of the number two engine and a diversion.