Synopsis
On 6 December 2010, at approximately 11:15 UTC, TAAG flight DTA-651, operated by a Boeing 777-200 (registration D2-TEF), experienced an incident shortly after departure from Lisbon Airport. The aircraft had taken off from runway 21 at 11:11 UTC, heading southwest over the Tagus River, and began a left turn to follow the assigned route.
Flight Details
As the aircraft approached 5,000 feet, the right engine (engine #2) suffered a loss of N1 (low-pressure compressor) speed, accompanied by an increase in exhaust gas temperature (EGT) and engine vibration. The vibration decreased when the power lever was retarded. Simultaneously, an EICAS message indicated abnormal behavior of engine #2. The crew discontinued the climb, stabilized the aircraft at 5,000 feet, and performed the appropriate checklists. They then proceeded for an approach and landing back at the departure aerodrome. Approximately ten minutes later, engine #2 was shut down, and a single-engine landing was executed without further issues at 11:32 UTC, on the same runway, 21 minutes after takeoff.
Debris Report
During the event, the GPIAA (Portuguese aircraft accident investigation authority) received notifications from the Lisbon Airport Operations Supervisor and the Public Security Police (PSP) of Setúbal and Almada, reporting that debris from the aircraft had fallen over the city of Almada. The debris caused damage to several vehicles and houses.
Investigation
The GPIAA opened an investigation immediately after notification. The investigation team conducted an external inspection of the aircraft, secured the flight data recorders (SSFDR and CVR), and initiated inquiries into operational, human, and material factors. Meteorological conditions at the time, as indicated by METAR reports, showed light rain only after the landing, with cloud cover that influenced the crew's decision to land with a mass above maximum landing weight (MLM).
The flight crew consisted of two pilots, both appropriately qualified for the aircraft type and route. Their licenses and medical certificates were valid, and training and checking programs had been completed. No evidence of significant deviation from standard operational procedures was found at this preliminary stage. The investigation continued with analysis of data from the aircraft condition monitoring system and the flight data recorders.
At this preliminary stage, no probable cause has been determined.