Date: 201711
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Takeoff / Launch
Airspace: Class B ZZZ
ATC / advisory: Tower ZZZ
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: Captain; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Weight And Balance; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor; Inflight Event / Encounter Bird / Animal
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Returned To Departure Airport; Flight Crew Landed As Precaution; General Maintenance Action
Contributing factors: Aircraft; Environment - Non Weather Related
Primary problem: Aircraft

Narrative: There was no weather or bird activity reported in the area. Previous aircraft that departed did not report any birds in the vicinity of the airport. We began the takeoff roll in VFR conditions. At positive climb rate I called for gear up. Shortly after the gear came up and at approximately 800 feet AGL; I heard a loud bang and felt a slight yaw to the left. Auto pilot was not engaged and the auto throttle was engaged. No rudder input was required to maintain our flight path. I immediately scanned the engine instruments to verify that they were both operating normally. No abnormal engine indications were noted; and the plane was flying normal. Both the Captain and I noticed a burnt smell in the aircraft and assumed we had a bird strike. The Captain [advised ATC] and requested vectors for an immediate return to the airport. Tower informed us that they saw smoke come from the engine; but seemed to be normal. We were directed to climb to 4000 feet and vectored for a left downwind. All indications were normal and the aircraft was handling normally.Once the autopilot was engaged; the Captain accomplished the after takeoff checklist; and I programmed the FMC for our return. I also sent the divert message to notify the company of our planned return. I called for the approach descent checks and briefed the visual backed up by the ILS. We discussed the possibility of losing the number 1 engine on final and the possibility of using flaps 15 for a single engine landing. On our base leg; I called for the approach checklist as we started to descend. Once on final; I called for gear down and flaps 15 and the landing checklist. Prior to the final approach fix; I called for flaps 30. The landing was normal. Tower directed us to contact ramp. We asked for the fire trucks to see if there were any visual indications of damage to the number 1 engine. They reported no issues; and followed us [to] the gate. I accomplished the after landing flow and the Parking checklist.Once at the gate; the Captain remained in the flight deck to accomplish the maintenance write up for the bird strike and overweight landing. I walked out to the ramp to inspect the number 1 engine and noticed the bird strike at the 10 o'clock position.I believe we handled the event appropriately and safely. Although there was no apparent damage to the engine; I believe our return to the airport was prudent.


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


Synopsis: B737NG flight crew reported returning to departure airport after experiencing a bird strike at 800 feet AGL on initial climb.