What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Flap attach hardware order

Draker

Well Known Member
DWG14A calls out the following hardware to attach the flap rod end to the flap:

K1000-4 PLATENUT
AN960-416L WASHER
AN936A416 INTERNAL LOCK WASHER
CM-4MS 1/4 C 1/4 ROD END BEARING

Is this the correct order for the hardware? In other words, lock washer against the rod end or lock washer against the flap FL-706B plate? I was planning to just assume that Vans hardware call-outs are always in the correct order, but you know what happens when you assume.

Additionally, the plans specify to use loctite or equivalent to ensure the rod end does not back out of the platenut. Any particular loctite? I was planning to use just regular hardware store blue loctite.
 
Callout order

The callout order sounds correct because normally the star washer goes under the head of the bolt, which in this case is the stud on the rod end bearing. If the star washer went under the flat washer against the flap bracket then what is it preventing from turning? (i.e. nothing)

I would also use the loctite blue 243 in case there is a need to be able to remove the bearing in future.

And of course double check your jam nuts are tight, as an aside! ;)
 
Star washer position

The callout order sounds correct because normally the star washer goes under the head of the bolt, which in this case is the stud on the rod end bearing. If the star washer went under the flat washer against the flap bracket then what is it preventing from turning? (i.e. nothing)

I would also use the loctite blue 243 in case there is a need to be able to remove the bearing in future.

And of course double check your jam nuts are tight, as an aside! ;)

The order of the flat washer and star washer is not important from a locking point of view (the flat washer is providing only friction due to compression) but it is important for which part gets scored up when the assembly is installed and removed and what options you have for replacing parts. The flat washer should go against the part that would be the most difficult or costly to replace (in this case the flap assembly) to prevent that getting scored up by the star washer(which is the whole point of having the flat washer in the assembly). The rod end bearing is easy to replace and so the star washer should be next to the rod end shoulder. The loctite provides the belt and suspenders approach to holding it all together.
That was the way it was explained to me back in the last century when I was an apprentice at an aircraft research center in the UK.
KT
 
Back
Top