B737-800
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe
Air Traffic Control Provided Assistance; Aircraft Aircraft Damaged; Flight Crew Overcame Equipment Problem; Flight Crew Diverted; Flight Crew Landed in Emergency Condition
Aircraft
Aircraft X was at cruise at FL 280 direct to ZZZ1. Mach .77. [Initially] airframe vibration; fluctuating N1; EGT engine #1 vibration 1.3. Engine # 2 vibration .3. Indicated. I immediately disengage Autothrottles and reduced thrust #1 to approx 60 % N1 to stabilize engine parameters and called for QRC check list and then continue to QRH. FA (Flight Attendant) chimed reporting flames and pulsing flashes out of left engine. We [notified ATC] and determined ZZZ was closet suitable emergency landing airport approx 105 nm to the south. Made ACARS report 7700 to company for ARFF (Airport Firefighting and Rescue); #1 Engine Failure and ZZZ destination. Requested immediate descent for RWY XXR. All checklist complete descent FLT IDLE both engines. ATC cleared direct ZZZZZ maintain 2000 feet. I briefed FA on situation on diversion; and that we had an engine problem which at this point they were fully aware. I told them I expected a precautionary landing which I briefed; and any non-routine landing considerations. I made a passenger PA as to the situation and that I expected a normal landing and to expect to see safety vehicles present around aircraft. Prior to intercepting final approach course and landing I confirmed with the FA that they had cabin ready for landing which they confirmed. Upon intercepting GS LOC flaps 30 at approx 2000 feet I increased thrust both engines to stabilized approach. As ENG # 1 approached 60% N1 vibration increased to unacceptable limits. I immediately reduced thrust to idle and continued to a single engine landing. Touchdown was smooth and normal. I brought aircraft to a stop on the RWY and made PA for passengers to remain seated. ARFF determined no fire; no fluids. I briefed FA and made sure cabin was secure. I made a passenger PA to assure passengers that the situation was under control and that we would now continue to the gate for deplaning. ARFF followed to the gate. I talked to the ARFF commander and released them when all passengers had deplaned. Post flight inspection with maintenance we observed unusual smoke in tailpipe; normal infrared signature; and oil site glass indication zero. Flight and cabin crew proceeded to hotel.
B737 Captain reported diverting due to failure of the left engine in cruise.