Investigation Summary
Flight 8622 was conducting a night approach to Trabzon's Runway 11 in rainy conditions with reduced visibility. During the final stages of the approach, the crew reported that the First Officer, who was the pilot flying, accidentally pressed the TOGA button while attempting to disconnect the autopilot and autothrottle. Although the aircraft touched down, the flight computer reportedly remained in a 'go-around' logic. As the crew deployed the speed brakes and engaged reverse thrust, the autothrottle (which had not been fully deactivated) allegedly commanded the right engine to increase power to go-around thrust levels. This created a massive thrust asymmetry: the left engine was in reverse thrust while the right engine was at high forward power. The resulting yaw moment forced the aircraft to veer sharply to the left. The Captain took control but was unable to correct the trajectory before the aircraft exited the paved surface. The Boeing 737 plunged down a muddy embankment, where the nose and right engine bore the brunt of the impact, causing the engine to shear off and fall into the sea. As of late 2024, the Turkish Directorate General of Civil Aviation (SHGM) has not released a final report, leading to significant delays in official confirmation of the pilot statements.
Final Conclusions
While pilot statements and unofficial reports highlight the accidental TOGA activation and the crew's failure to ensure the autothrottle was fully disengaged, these remain unconfirmed by the Turkish Directorate General of Civil Aviation (SHGM). The asymmetric thrust condition is the leading theory for the loss of directional control. The lack of fatalities was attributed to the aircraft becoming bogged down in soft, wet mud on the slope, which prevented it from sliding completely into the Black Sea. The aircraft was declared a total loss.
Photographic Evidence (1)
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Systems & Failure Modes
Autothrottle / TOGA
The Take-Off/Go-Around (TOGA) system automatically sets engine thrust for a climb. An accidental press during landing prevented the engines from remaining at idle/reverse, leading to asymmetric thrust.
CFM56-7B26E Engines
The aircraft was powered by two CFM International turbofans; the right engine responded to the autothrottle's go-around command while the left was in reverse.
Interesting Facts
- 01The aircraft was a 5-year-old Boeing 737-800 named 'Zeynep'.
- 02The right engine (Engine No. 2) completely detached during the slide and was lost in the sea.
- 03The runway at Trabzon (Runway 11) has a Landing Distance Available of 2,640 meters.
- 04Visibility at the time of the accident was approximately 4,000 meters in light rain.
- 05The aircraft was removed from the cliff face five days later on January 18, 2018, using heavy cranes.
Safety Actions & Advisories
Crew Training Review
The accident prompted reviews of Pegasus Airlines' training regarding autothrottle disengagement procedures and the prevention of accidental TOGA activation during the landing phase.
Location
ACCIDENT SITE · Coordinates taken from the wikipedia geotag.