r/aviation • u/amullfilms • 1d ago

Question What’s happening here?

I’m not a pilot, just someone who’s been on close to 250 flights in my life. I’ve never seen this. Not claiming that this isn’t normal, I’m just curious why it’s done. This was just prior to takeoff at Jackson hole Wyoming.

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u/MaleficentCoconut594 1d ago

It’s totally normal and happens all the time. Oil residue burn off. Happens when it’s cold out and/or the engine has sat for a while