Preliminary eyewitness reports are often fairly unreliable, so I won't put much weight into those. In any case, flames and vibrations can be explained by the en

Preliminary eyewitness reports are often fairly unreliable, so I won't put much weight into those. In any case, flames and vibrations can be explained by the engines experiencing a compressor stall [1] due to turbulent airflow or the aircraft otherwise operating outside of its design envelope [2]. [1] https://www.youtube.com/watch?v=MQWYhsYfMxE https://www.youtube.com/watch?v=MQWYhsYfMxE (Boeing Training Video on Compressor Surge/Stalls) [2] https://en.wikipedia.org/wiki/Compressor_stall#Causes https://en.wikipedia.org/wiki/Compressor_stall#Causes