Did a FH booster engine catch fire on the way down?

[IainMcClatchie]

This video shows an uninterrupted view of one booster's entire flight.  I've started it at 7:44, ten seconds later at 7:54 you can see a burst of smoke start from one of the engines.



This engine glows red at 7:36 and 7:41.

A second engine (not the center engine) appears to glow red at 7:46, 7:53, 7:55, and 7:58.

Does anyone know what these on-again, off-again red glows are?

[deruch]

This video shows an uninterrupted view of one booster's entire flight.  I've started it at 7:44, ten seconds later at 7:54 you can see a burst of smoke start from one of the engines.

https://www.youtube.com/watch?v=59pY74ZhQ50?t=7m44s

This engine glows red at 7:36 and 7:41.

A second engine (not the center engine) appears to glow red at 7:46, 7:53, 7:55, and 7:58.

Does anyone know what these on-again, off-again red glows are?

What you're seeing is the result of flowing LOX through an engine that is very hot and sooty ----> Hot soot combines with LOX to make flames.