What happened
On April 25, 2005, at 15:10 UTC, an Iberia McDonnell Douglas MD-87, registration EC-EXF, was performing a scheduled commercial passenger flight from San Sebastián Airport to Madrid-Barajas. During the takeoff roll on runway 22, the aircraft encountered a large flock of seagulls located on the runway and its surroundings.
As the aircraft became airborne, several birds impacted the airframe. Specifically, birds were ingested into the right engine, causing the breakage of fan blades and inducing severe vibrations. The flight crew observed flames emanating from the right engine, as confirmed by air traffic control. In response, the crew shut down the damaged engine and deployed an extinguisher. The aircraft declared an emergency and performed a right-hand turn around Mount Jaizquibel to initiate an immediate return to the departure runway.
During the landing phase, approximately eight minutes after takeoff, the crew utilized the thrust reversers on the remaining operational engine. During this braking process, the left engine suffered a failure characterized by a compressor stall and apparent fire. The aircraft came to a stop in the final third of the runway. Emergency services met the aircraft, and all 65 passengers and the crew were evacuated safely via the forward stairs. No injuries were reported, aside from one case of anxiety.
The investigation
The CIAIAC examined the flight data recorder (DFDR) and cockpit voice recorder (CVR) to reconstruct the sequence of events. The DFDR analysis confirmed that the right engine experienced a sudden spike in vibration levels and a significant increase in exhaust gas temperature (EGT), reaching a peak of 718 °LT, which exceeded the maximum takeoff limit of 630 °C. The investigation also analyzed the engine's vibration monitoring systems and the impact of the bird strike on the engine's internal components.
Findings
- The primary cause of the initial engine failure was a bird strike involving several seagulls during the takeoff phase.
- The ingestion of birds into the right engine caused structural damage to the fan blades, leading to severe vibrations and an engine shutdown.
- A secondary engine failure occurred on the left engine during the landing roll due to a compressor stall triggered by the use of thrust reversers.
- While the airport's Aeronautical Information Publication (AIP) included a warning regarding the presence of birds on the runway, the specific flock was not communicated to the crew prior to takeoff.