Date: 202101
Local time of day: 1201-1800
Location: ZZZ.ARTCC, US
Flight conditions: VMC
Weather elements / visibility: 10
Light: Dusk
Aircraft: Citationjet (C525/C526) - CJ I / II / III / IV
Operator: Air Carrier
Operating under: Part 135
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: AC Generator/Alternator
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Second reporter function: Pilot Flying; Captain
Anomaly: Aircraft Equipment Problem Critical; Inflight Event / Encounter Bird / Animal
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Aircraft Aircraft Damaged; Flight Crew Diverted; Flight Crew Overcame Equipment Problem; General Maintenance Action; General Flight Cancelled / Delayed
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: We departed ZZZ en route to ZZZ1. Captain and myself; First Officer; noticed a light harmonic droning noise during climb out but no vibration. About 30 minutes after takeoff while in cruise at FL370 the LH Gen Master Caution illuminated. We ran the QRH and reset the LH generator. At this time the generator did not come back online. We then decided to reduce the electrical load on the remaining generator. The QRH indicated to land as soon as practical. With one hour and 20 minutes left in flight we elected to continue to our destination with the remaining generator.At this time we informed Dispatch. Along our route of flight we determined which airports were suitable for landing in the event we lost our right generator. This proved to be beneficial due to the events that happened down the road. About 40 minutes after the LH generator failed the LH engine rolled back. N1 fell back to almost idle and the ITT dropped immediately as well as fuel flow. We then advised ATC of our engine problem and determined ZZZ2 was suitable and asked ATC for radar vectors direct to ZZZ2.Captain pulled back the power lever on the LH engine at which time we noticed the engine spooled back up but was fluctuating erratically. We started our descent since we were only about 65 nm from the airport. During the descent the engine seemed to stabilize. The droning noise became louder and strangely seemed to come from the front of the aircraft. No noticeable vibration though. Descending into the pattern at ZZZ2 the droning noise become pretty loud and we felt a thump in the fuselage. The thump we latter determined to be a bird strike on the RH wing. (No damage to wing). Conditions on the field were night VFR and the runway was dry. With the loud noise that appeared to come from the front of the aircraft Captain decided during landing to hold the nose off as long as possible. We landed with no issues and no structural damage. We then taxied off the runway and were met with the Airport Fire Department. Priority handling was not requested; but fire was staged as a precautionary measure. As we were taxiing to Company; a repair station on the field; Captain gently pushed up the LH throttle at which time we both noticed it had spooled down by itself. He then went to idle cut-off. Being that Fire was following behind the aircraft a firefighter advised us that he saw a very large puff of smoke from the back of the LH engine when it died. Employees from Company were waiting on the ramp also saw the same plume of smoke. Upon the walk around inspection we found no evidence of structural damage to the engine or any damage where the bird struck had occurred on the right hand wing. The fan blades turned easily. We did observe underneath the LH engine cowl large black streaks from the starter generator cooling exit.


Second narrative: [Report narrative contained no additional information.]


Synopsis: CE525 Flight Crew reported the failure of the  L/H Generator and a Roll Back on the L/H Engine resulted in a diversion.