Lock washers, no loctite, that would gum up the blind nuts and eventually have a bad day.
AFTER assy, I put a little Goop (Shoe Goo) Automotive glue on the screw, in ten minutes , by the time I ready to fly , it is sticky and won;t let the even a severely loose bolt rotate out. It's kinda like outboard loctite. Goop comes in different formula's , auto, home and Garden, house hold...it's mostly the same stuff...I use Auto and household....
http://www.amazinggoop.com/amazinggoop/index.html
http://www.amazinggoop.com/amazinggoop/index.html
http://www.amazinggoop.com/amazinggoop/index.html
http://www.amazinggoop.com/amazinggoop/index.html
I use it on every bolt during assy of my gassers...like when I have to put on removable stabs on my Yak,,,,the bolts get Gooped, My cowl screws, on every servo arm screw..., every linkage screw., just about anything that I don't want to come apart, BUT need to remove regularly.
Loctite has it's place, but I use Goop on a lot of stuff....just be ready to pull on it to get it off...it is tough stuff. The best silicone type glue I have ever used.
I get it at ACE Hardware. Paint section has most formulas....Auto section has the automotive variety. They almost all the same, IMO.
So, Goop them bolts , fly it, then pull it off. I don;t like using loctite on blind nuts ....