Creating a good airframe ground

[John-G]

Van?s plans call for attaching a ground wire to a hole in the seat ribs using a bolt, flat washer and a stop nut to create a ground point for an electrical connector. I?ve already removed the primer down to shiny metal where the mounting hole for the ground wire is located.

My question is ... I?m wondering if there is any merit for substituting the flat washer for a star lock washer with internal teeth? My thinking is the star lock washer will bite into the aluminum, thus creating a better overall ground than just using a flat washer ? especially over time.

However was wondering, in general, if using star washers in a vibrating aircraft is a bad idea? Is there a significant possibility of stress risers being created by the star washer biting into the aluminum?

What is the best way to proceed ... Go with the star washers or install flat washers?

[Dbro172]

Plenty of good grounds flying around without star washers cutting teeth into the aluminum. Use your multimeter to verify the resistance and you'll find that a plain washer is just fine.

[Walt]

See FAA AC 43-13 Chapt. 11, table 11-4 for proper ground connecting method (no star washers).

[John-G]

Thanks for the input guys. Will move forward using flat washers at ground points and forget about the star washers.