Date: 202104
Local time of day: 1201-1800
Flight conditions: VMC
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
ATC / advisory: Center ZZZ
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Communication Breakdown
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor; Inflight Event / Encounter Other / Unknown
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Diverted; Flight Crew Landed in Emergency Condition; General Maintenance Action; General Flight Cancelled / Delayed
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: XA:05Z. FL390 with autopilot on. First Officer 1 said he smelled fumes. I agreed; donned oxygen mask. As a precaution we unplugged our respective iPads from the electrical outlet. After a brief period; we did not smell any odor/fumes. XA:20Z crew change and a wakeup call was made to First Officer 2. XA:25Z odor returns definite electrical/acrid smell. It appeared to be coming from the flight deck ventilation system. I donned oxygen mask and established communication and directed First Officer 1 to check cabin. No fumes detected in cabin. Shortly afterwards; First Officer 2 appeared. We briefed him and had him go check the cabin and flight attendant bunk to check for fumes/odors. XA:28Z He reported no odors detected in cabin. XA:30Z I gave aircraft control to First Officer 1. First Officer 2 and I ran the Smoke; Fire or Fumes unannunciated checklist. The checklist directed us to turn off the IFE/Pass (in flight entertainment) and both recirculating fans; we no longer could smell the fumes on the flight deck. After completing all steps as required by the checklist I announced 'Smoke; Fire or Fumes unannunciated checklist complete'. Since we could not positively confirm that the smoke/fumes/fire was completely extinguished; I directed First Officer 1 to notify ATC and obtain clearance direct to ZZZ. First Officer 2 established communication with Dispatch and Maintenance Control.  First Officer 1 continued flying the aircraft and monitored our communication with Maintenance Control and Dispatch. First Officer 2; First Officer 1; Maintenance Control; Dispatch and I were in agreement with divert to ZZZ. XB:00Z I briefed approach and landing. Then assume control of aircraft from First Officer 1. XA:40Z; It was a normal approach and landing. We taxied clear of active runway and stopped.NOTE: ATC or [company] were not able to establish phone communication with ZZZ. We were not able to establish VHF communications prior to landing. We landed at XB:40Z and our first contact with station approximately XF:00Z. I utilized the crew; everyone had input and their input was valuable. Together we assessed the problem and agreed on best course of action. First Officer 1 and First Officer 2 made my job extremely easy due to their airmanship; systems knowledge and most important their willingness to contribute. I am honored to have them on the team. We debriefed the flight utilizing our crew debriefing card. The note for pilot control lighting (PCL) is under the miscellaneous section. This information is vital and should be in the frequencies section. ATC and [company] were unable to reach anyone on ZZZ. Once communication was established with ZZZ; the station performed outstanding.




Synopsis: Captain reported a fumes event during cruise resulting in a diversion.