Aileron bellcrank and pushrod assembly

[TShort]

In the KAI pages 28-19, 28-20 and 28-21 dealing with insertion and assembly of the aileron pushrods there is a difference which I am unsure about:

On page 28-20, the callout is only for one washer for each rod end assembly.



For each of the other two assemblies, there is a washer under the bolt head and the nut:



I’m being extra cautious since this involves flight controls. Can anyone think of a reason for this, or could it be an error in the instructions? It’s the same rod end, same bolt size, same lock nut, etc.

THomas

 

[Ironflight]

There are tims when you put a washer under the head of the bolts for various reasons. One is if you are going to be turning the bolt (not the nut) - that is to keep from galling the part. Another (possibly this case) is to lift the bolt just the thickness of the washer to give you clearance at the other end. A third reason is that there is an error in the drawing of course….. but I’d suspect that for this, they want to lift the bolt just a tiny amount so that the other end of the bolt doesn't hang up on something. It’s worth checking.

 

[TShort]

Thanks, Paul - and good call!

Once in assembly and under further inspection, if there is a washer under the bolt head on the small aft pushrod the bolt head does not clear the mixer box (just barely touches).

I don’t see any potential interference on the forward part of the bellcrank, but will proceed as per plans.