Date: 201810
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: Mixed
Weather elements / visibility: Thunderstorm; Icing; Rain
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Climb; Takeoff / Launch
Airspace: Class B ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Compressor Bleed Valve
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Human factors: Troubleshooting; Workload
Anomaly: Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition
Contributing factors: Weather; Aircraft
Primary problem: Aircraft

Narrative: During takeoff detected odor during climbout. It didn't last long in the climb and was not noticeable during cruise flight; during descent into ZZZ passing 26;000 or so we started smelling this odor again; while descending further the smell became stronger. The flight attendants in the forward cabin called to say they were smelling a strong odor / fume up in the forward galley area by the cockpit door. Stated it did not extend into the passenger cabin area. As the odor / fume became stronger in the cockpit. I [notified ATC] and we donned our oxygen masks and ran the QRH.We were in significant weather deviating around thunderstorms moderate turbulence; and moderate rain with icing.Note: engine anti-ice was on throughout our descent. Wing anti-ice was on for approx. 5-10 minutes during descent. Odor and fumes seemed confined to the cockpit and forward galley only. Once down around 3-4;000 most of the fume/odor was gone. Successful landing on Runway 4R with winds 080 feet at 26 gusts 34 knots.Aircraft just came from ZZZ1 after a heavy check. It was ferried before this flight. I suspected a left engine bleed issue or fume due to its presence primarily in the cockpit and its recent heavy check. Smell was similar to paint on an exhaust pipe or a BBQ that gets very hot for the first time. No visible haze or smoke was present but the fume was definitely strong enough to require use of the quick don masks for safety. Some mild eye irritation was noted in the last 30 minutes of flight. The cabin crew reported that the fumes were not affecting them or present in the main cabin.Would like to extend our sincere thanks to Center; Approach control and tower/ground controllers for their outstanding support during this event. Also the ready support by ZZZ's crash fire rescue team that responded to our [situation]. They were with us until all the passengers were off the aircraft.I also would like to commend my crew; starting with my First Officer; for his professional performance during this inflight event that was as complicated as it gets; trying to evaluate the source; coordinate with ATC when needed; working with flight attendants and assistance with avoiding severe weather. He was the most important player in this event and his skillset and training was evident all along the way. Kudos for a job well done. Secondly; appreciation for an outstanding job by our flight attendant crew for their exceptional job of preparing our passengers and the cabin for our arrival in this situation. It was a total team effort to get us all to the gate safely.




Synopsis: B737-800 Captain reported fumes in the cockpit and forward during climb; clearing in cruise; and returning on descent.