Date: 201601
Local time of day: 1201-1800
Location: ZZZZ.Airport, FO
Flight conditions: VMC
Light: Daylight
Aircraft: A320
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Takeoff / Launch
ATC / advisory: Tower ZZZZ
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: First Officer; Pilot Flying
Anomaly: Aircraft Equipment Problem Critical; Ground Event / Encounter Person / Animal / Bird
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Aircraft Damaged; Flight Crew Landed As Precaution; Flight Crew Returned To Departure Airport; General Maintenance Action
Contributing factors: Aircraft; Environment - Non Weather Related
Primary problem: Environment - Non Weather Related

Narrative: Encountered a seagull strike in left engine. Vibration noticed immediately after 120kts with buzzing sound from engine. Takeoff continued as no other abnormal engine indications. Capt stated 'continue' at 140 kts. Rotated 145 kts. Normal climb out but noticeable vibration and noise. After 2000 feet checked engine ECAM and #1 N1 vibration showed 9.1. All other engine indications normal. FO stated he saw a bird on left side and believed we hit it. Captain did not see bird. Leveled off at 5000 feet and vibrations subsided with power reduction. Crew agreed a return to land was prudent. Notified ATC; FAs; and passengers. Arrival uneventful. Landing flawless by FO. MX inspection revealed damage to several fan blades but no apparent core damage. Feather samples taken. Crew re-assigned for next day duty.


Second narrative: On takeoff from ZZZZ; I noticed a single light tan bird gliding over the runway in front of the aircraft moving from right to left as we accelerated through approximately 90 kts. Shortly afterward; a loud buzzing began from the left engine. At this point we were already past 100 kts. At approximately 120 kts; the Captain verbalized 'Continue.' All indications on the engine were normal and I executed a normal T/O. We cleaned up the aircraft and the Captain worked to identify what had happened. Vibration on the #1 Engine was high and flashing green. At a level off; as the power decreased the vibration stopped flashing and the noise from the #1 engine decreased. As climb power was restored; the noise level increased and the vibration indication began to flash again. Captain coordinated with ATC to level off and return to ZZZZ. Power setting on the engines remained below climb power for the remainder of the flight and vibration did not flash again. Other engine indications were normal; we received no ECAMs and the plane flew w/o difficulty. We concluded a normal approach and landing. After shutdown; Mx identified major damage to the blades in the #1 engine.


Synopsis: A320 flight crew reported encountering a bird strike at high speed during the takeoff roll. The takeoff was continued; however a significant vibration in one engine was noted. They reduced power on the affected engine and safely returned to the departure airport; where major damage to the engine was discovered.