Interesting, what defines their lifetime in age?

CF6-80 Series motors have the #1 fan blade "1" stamped each side of the blade dove tail post on the fan disc. You cannot see it with the spinner on. counting is counterclockwise looking aft and i believe #5 blade is also marked on the spinner disc. my old company used a paint mark on the spinner to indicate#1 fan blade not to be mistaken for the paint mark on the spinner offset hole. This ensures that the spinner goes back onto the correct position on the fan disc. High N1 vibs on these engines was usually corrected by lubing the fan blade dovetail posts on the fan disc as well as lubing the fan blades.

319/320

on the Trent there is an asterisk on the spinner extension piece, it's next to where all the balance weight screws are fitted. As for sharpies - NO, NO, NO...

For Lomopaseo - the blades are 'lifed' just like other rotating components in the engine, only the blades are normally 'Cat B' lives, not 'Cat A' lives, can be found in Chapter 5 of the Enigne Manual, and they are governed in cycles.

Regards,

N1 Vibes

seen the light
 

Okay, I have seen the asterix, fan not spinning, on the hub.
Thanks for the responses from the techies! Better informed.