Date: 202010
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Light: Night
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class A ZZZ
Aircraft component: Turbine Engine
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Human factors: Time Pressure; Troubleshooting
Second reporter function: Pilot Flying; Captain
Anomaly: Aircraft Equipment Problem Critical
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Aircraft Equipment Problem Dissipated; Aircraft Aircraft Damaged; Flight Crew Landed in Emergency Condition; Flight Crew Diverted
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Climbing out; approximately XX00Z; the left engine had loss of thrust associated with compressor stall / surges. Flight attendants rang the call button and indicated they heard loud banging and wanted to verify we heard the same. We shallowed our climb then leveled off at FL 280 and [advised ATC]. Subsequent flight attendant chime indicated they saw flames had extended aft of the #1 engine. We had already begun to tackle the surge / stall QRC followed by QRH checklist when they called advised of flames. We recognized and agreed that ZZZ was our best option due to proximity (80 miles roughly ) off our nose with optimum field capabilities. We coordinated with flight attendants and talked with a non-rev commuting Company Captain who had been sitting on left side of cabin and had seen the flames. During this process; we coordinated with ATC for direct and began a descent to ZZZ [and] fired off a quick message to Dispatch indicating engine malfunction and plan to divert. We coordinated with crew of the precautionary landing and advised passengers of our intentions. In the descent we completed the appropriate checklists; acquired the [weight and balance] data for landing in addition to brake cooling then were vectored for a visual approach to [Runway] XXL. We landed uneventfully and taxied clear of the runway and we were met by Fire and Rescue. We shut down the #1 engine and awaited CFR to evaluate. CFR gave us the all clear and we taxied to gate and began to coordinate with all appropriate personnel.


Second narrative: Normal climbout passing FL 282.  Initially heard banging outside of aircraft followed by a reduction in climb; decreasing airspeed and aircraft vibration.  Immediately followed by a call from the A F/A (flight attendant) reporting flame emanating from #1 engine.  Engine problem was confirmed in the cockpit by high temp (800 EGT) and diminished N1.  My F/O (First Officer) immediately notified ATC that we have an engine issue and need to maintain FL 280. I told him to [request priority] at that time. I reduced the thrust lever to observe changes in engine indications. The vibrations ceased and temperature reduction. We both believed we had a compressor stall. We were holding FL 280 on one engine; albeit with excessive thrust on #2 engine.  F/O asked for lower and we were cleared to FL 240. We had two jumpseaters onboard; so I got an experienced set of eyes on the engine.  He confirmed all that we knew and that the engine no longer had flames coming from the tailpipe. Assessing the non-normal together; I called for the QRC (quick reference checklist) Engine Limit or Surge or Stall Checklist.  The QRH (quick reference handbook) confirmed our assessment. We completed down to Step X (QRH) at that point. An engine shutdown was not required; but thrust lever remained at idle for remainder of flight.  ZZZ was 80 miles from our present position and we agreed was the nearest suitable airport.  ATC cleared us direct. While I was PF (pilot flying); F/O communicated with F/A's and passengers.  I sent a message to Dispatch about our diversion.  We ran the Diversion Checklist.  F/O ran weight and balance data for a 'One Engine Inoperative' approach and landing data.  We planned for and flew a 'One Engine Inoperative Landing'.  An uneventful landing in ZZZ culminated with a check of the engine/damage by Emergency Personnel.  We taxied under our own power to the gate.


Synopsis: B737 flight crew reported engine compressor stall and surges resulted in divert to precautionary landing.