Date: 202009
Local time of day: 0601-1200
Location: ZZZZ.Airport, FO
Flight conditions: VMC
Light: Dawn
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Ferry / Re-Positioning
Flight phase: Cruise
Airspace: Class A ZZZZ
ATC / advisory: Center ZZZZ
Aircraft component: Turbine Engine
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Second reporter function: Captain; Pilot Flying
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Air Traffic Control Issued New Clearance; Aircraft Aircraft Damaged; Flight Crew Inflight Shutdown; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Landed in Emergency Condition; Flight Crew Diverted; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Captain and I [deadheaded] to ZZZ to pick up a 737-800 to ferry back to ZZZ1 due to a loss of system A hydraulic fluid. Preflight showed no leaks and everything ok with the aircraft. I was PM and upon takeoff the Master Caution light came on for engine driven hydraulic pump for system A. The light went out and continued. Abeam ZZZ2 the master caution came back on for engine driven hydraulic pump number 1 system A. I pulled out the QRH and ran the Hydraulic Pump Low Pressure checklist which had us turn the pump switch off. With quantity and pressure still good using the electric pump we decided to continue to ZZZ1. Maintenance techs on the aircraft agreed with the decision. Soon after passing ZZZZZ intersection the number 1 Engine Oil Filter Bypass indication on the upper engine MFD illuminated. I pulled out the QRH and we decided to request a lower altitude since we knew we could not maintain level flight with one engine at idle. We asked for a descent to FL 200 and told them we were working on a problem with our left engine. Since the OIL FILTER BYPASS indication remained illuminated the next step per the QRH was to shut the engine down. As a result we had to land at the nearest suitable airport. We decided that ZZZ3 was the best choice since it was close the weather was good and we were both familiar with the airport. I continued with the checklist as [the Captain] flew the aircraft; [requested priority handling]; and requested the diversion. We were cleared direct to the airport and a descent to FL 70. Shutdown and descent proceeded normally with me accomplishing the shutdown and [the Captain] continuing to fly and maintain communication with ATC. We then moved to the one engine inoperative and landing checklist which included calculating single engine landing distance. Hydraulic system A at this point had gone down to 25 percent. We prepared for the possibility of losing total system A pressure and a manual gear extension but was not a factor as the gear operated normally; [the Captain] performed a visual approach and landing with a safe landing in ZZZ3. We then sent a message to dispatch via ACARS that we were safe on the ground.


Second narrative: First Officer and I deadheaded to ZZZ to pick up a 737-800; which had been down for maintenance due to failure of the number 1 engine driven hydraulic pump failure and loss of system A fluid. Upon arrival we did our normal preflight and found no problems with the aircraft. The 3 Tech OPS employees who fixed the aircraft were embarked and we prepared to fly.Start up; taxi; and takeoff were normal. I was flying pilot and [First Officer] was monitoring. Early in the climb master caution light for the hydraulics came on and [First Officer] noted that the low pressure light for the engine driven hydraulic pump on engine 1 was on then quickly went out. Thinking it was anomaly with sensor and hydraulic quantity and pressure normal we continued. We were abeam ZZZ2 and the master caution for Hydraulics once again illuminated and [First Officer] noted the Low Pressure light for engine driven hydraulic pump on the left (number 1) engine was illuminated and stayed on. [First Officer] pulled out the QRH and proceeded to run the Hydraulic Pump Low Pressure checklist which lead to the pump being turned off. With quantity and pressure still good using the electric pump we decided to continue. We did get one of the Maintenance Techs to come to the flight deck and we showed and conversed with him about the issue. Nothing changed our thought process so we continued.Soon after passing ZZZZZ intersection and headed directly to ZZZZZ1 intersection; the number 1 Engine Oil Filter Bypass indication on the upper engine MFD illuminated. [First Officer] once again pulled out the QRH and we decided I would continue to fly and talk and he would run the checklist. We were at FL300 and decided to request a lower altitude as we knew we could not maintain level flight for long with one engine at idle. We asked for and received a descent to FL200 and told him we were working on a problem with our left engine. [First Officer] worked our way through the checklist resulting with the OIL FILTER BYPASS indication remaining illuminated. Per the checklist the next step was to shut down the engine and as a result of that we would need to land. We chose ZZZ3.[First Officer] continued the checklist as I [requested priority handling] and requested to divert. We were cleared direct the airport and a descent to 7;000. Shutdown and descent proceeded normally with [First Officer] completing the shutdown checklist. With the engine secured we moved on to the one engine inoperative and landing checklist to include the non-normal single engine landing distance. As we got closer to ZZZ3 the hydraulic issue took another turn. The quantity began to change first climbing to 106 percent and then slowly starting to decrease to mid-70 percent and then working its way down slowly till as we were coming down final it was in mid-20's. [First Officer] brought up the possibility of losing the 'A' system; so both of us were both prepared should that happen. Fortunately we did not have to run that checklist. Visual approach and landing was uneventful and normal. Landed and taxied to parking spot.We sent a message to Dispatch using ACARS that we were safe on the ground. The call I got after we had been on ground for 15 min. or so from the FODM gave me the feeling that it didn't go through but it was sent. It was confirmed by maintenance that in fact the 'A' system was depleted to about 25 percent and still leaking.


Synopsis: B737 flight crew reported inflight shut down and diversion due to hydraulic system failure.