Date: 201811
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: B737 Next Generation Undifferentiated
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Second reporter function: First Officer; Pilot Flying
Anomaly: Inflight Event / Encounter Bird / Animal
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Aircraft Damaged; Flight Crew Returned To Departure Airport; Flight Crew Landed As Precaution; General Maintenance Action
Contributing factors: Environment - Non Weather Related
Primary problem: Environment - Non Weather Related

Narrative: Captain; Pilot Monitoring. First Officer; Pilot Flying. We were climbing through 3;500 FT MSL and accelerating to 250 KIAS when we struck a very large bird (perhaps a seagull or Canada goose). It impacted the radome on the Captain's side. It was the most violent bird strike that I have ever experienced. During the cabin crew debrief; our flight attendants seated by door 1L informed me that they too heard the impact. Bird remains covered the center portion of the Captain's windshield. We immediately checked for normal engine indications and reported the bird strike to Departure Control. There was no abnormal noise or vibration emanating from the radome and all pitot-static indications were normal. Passing 10;000 FT MSL; we did not select ECON Climb; but rather increased speed gradually to 280 knots and continued to climb. Again; there were no abnormal indications. Passing FL180; we attempted to contact Dispatch and requested a phone patch to [Maintenance] Airframes which took a few minutes to establish. We consulted with both [Maintenance] and Dispatch. I was concerned about the structural integrity of the radome and the fact that we had 3 hours of flight time remaining to [our planned destination]. Our Dispatcher conveyed that if we were to divert; return to [departure airport] was preferable. We discussed our options as a crew and elected to return to [departure airport]. We [requested a return to departure airport from] Center and took vectors to intercept the arrival. I reprogrammed the FMC for the diversion; got data for an overweight landing; conducted a brief with the cabin crew; briefed the passengers; reviewed the QRG Diversion Guide; reviewed the Airspeed Unreliable QRH; reviewed the FM Performance Non-Normal Section for Airspeed Unreliable Pitch and N1 settings at our weight; got the ATIS; set up for the ILS; briefed the ILS; assumed Pilot Flying Duties; and completed an uneventful overweight landing. In our cockpit crew debrief; 'What could we have done better?' my First Officer said he thought he could have helped me more. He did a superb job handling the flying and VHF 1. Prior to submitting this report; I called [Maintenance] to check on the outcome of the maintenance inspection. The maintenance inspection revealed delamination in the impact area which required removal and replacement of the radome.


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


Synopsis: B737NG flight crew reported returning to departure airport after striking a large bird during climb. Reporter stated the radome was damaged and had to be replaced.