Marking on front cone spinner

[loitranngoce]

Can U help me. I worked in B737 and A320 but I don't know clearly purpose of marking (whirl painting) on Engine front cone spinner. Can u list all purpose of it.
Thank you.

[Denny of Oakland]

There were two reasons for the cone marking;

1. To keep birds out so they could see it and fly clear.
2. So line maintenance could not get suck in staring at it like a propeller.

Neither work very well.

[loitranngoce]

Thank you so much.