Date: 201501
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Night
Aircraft: Large Transport; Low Wing; 2 Turbojet Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Initial Climb
Airspace: Class C ZZZ
ATC / advisory: Tower ZZZ
Second aircraft: Fighter
Reporter organization: Government
Reporter function: Local
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Situational Awareness; Time Pressure; Distraction; Confusion
Anomaly: Aircraft Equipment Problem Critical; Inflight Event / Encounter Bird / Animal
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Landed in Emergency Condition; General Declared Emergency
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Aircraft X was cleared for takeoff on runway XXR at XX00Z to meet his CFR time. As Aircraft X was flying past the control tower and over taxiway at approximately 600 feet; I observed large flames coming out of the back of what appeared to be the left hand engine. This was followed with several very loud booms that could easily be heard in the tower cab even with all the noise insulation in the tower cab. I heard in total roughly 5-7 loud booms with roughly as many flashes from the engine in addition to flames shooting out the back of the engine. The pilot radioed that he [had] a bad vibration and needed to turn around to land at the airport as soon as possible. The pilots then came back and stated they'd lost an engine and were requesting [the runway they had just departed from]. The conditions were VFR and I asked the pilot if they wanted to return and land on [the westerly facing runways]. They said they wanted XXR. I asked if they were able to maintain their own terrain and obstruction clearances so I could vector them below the MVA's. They said they would be able to and informed me that they would be leveling off at 1;500 feet. I issued a vector for Aircraft X to fly heading 360 to bring them back to the airport. I vectored the aircraft and continued attempting to get the pilots to get the airport in sight. As the aircraft was on the downwind it was reported that there was a possibility of FOD on the runway. I reported this to the pilots and asked if they would be ok with landing [on the left runway] instead. They agreed. I continued issuing vectors to the aircraft. As the plane was on a 5 mile base I turned the runway lights up to step 5 since the pilots were having a hard time finding the airport visually. They got the airport and runway in sight and I cleared the plane for a visual approach to runway XXL. As the pilots landed I asked them to state their intentions; they wanted to exit the runway and have the fire department examine the plane for any fire. As Aircraft X was off the departure end a flight of 2 fighter jets were on final for XXR. Their company informed them that there may be FOD on the runway so on short final; the flight of 2 went missed. I kept them runway heading and climbed them to 6;000 feet as coordinated by the local one controller and handed them off to the nearby sector in the TRACON so I could continue assisting Aircraft X.Nothing; they hit birds at night that were not visible from the control tower.




Synopsis: Local Controller reports of a departing flight that ingests birds on departure; loses engine one; and returns safely to the airport.