**THE-RFI-EMI-GUY** writes:

I was flying in an Air Jamaica jet many years ago and while cruising
noticed large reddish flames from the exhaust of the Rolls Royce engine.
How "normal" would that be?

It depends on the exact conditions. Were you cruising? Climbing?
Descending? What altitude? How did the engine sound? How long did the
flames last, and what did they look like, exactly?

Normally visible flames don't extend beyond the engine, although if you look
directly into the exhaust of a jet engine you may well be able to see glowing
internal parts. High-performance engines may glow externally as well. And of
course afterburners can produce long flames that extend well beyond the
engine. And so on.

There is jet fuel burning inside a running jet engine all the time, so a
visible flame isn't necessarily a cause for panic or concern.

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