NTSB alert - NUTS

[Jim Heffelfinger]

I just noted one of the NTSB Safety Alerts dealing with locking nuts. Am I seeing the photos captioned nylon as really fiber inserts?
http://www.ntsb.gov/doclib/safetyalerts/SA_028.pdf

[FlyingRon]

Look nylon to me (at least the left one, I can't really tell what's left of the right one).

[Scoot25]

The new one looks Nylon, old one is too corroded to tell. The Alert is for Nylon and Fiber inserts both though.

[martymayes]

Looks accurate to me.