Elevator misalignment

Just wanted to run this by the group,with the rudder off I have the elevators temporarily bolted on and both counter balance arms clamped to the horizontal stabilizer.When sighting across the trailing edge of the elevators seems they are off by almost 5/8 inch.Is this acceptable ?Ran a string across and left elevator is definitely higher.Thanks for the help,Dave. Also have an email into vans also

Take a picture and post it.

Jim Fogarty
RV-9A Flying

Future RV 9 Flyer said:

Just wanted to run this by the group,with the rudder off I have the elevators temporarily bolted on and both counter balance arms clamped to the horizontal stabilizer.When sighting across the trailing edge of the elevators seems they are off by almost 5/8 inch.Is this acceptable ?Ran a string across and left elevator is definitely higher.Thanks for the help,Dave. Also have an email into vans also

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The arms don't line up. You line up the elevators and clamp them in place with the tips and horizontal stab. Then drill the attachment hole in the arms. When done usually the arms are slightly out of alignment and that's "normal"

I have heard of the horns being off and you just drill for the most edge clearance average for the push rod heim bolt, but of course, check with headquarters to confirm.

when I clamped my elevator tips to both of the HS tips, the R trailing edge was higher than the L by something > 1/4" .... nearly 3/8" at the worst point. Vans told me it would be "aerodynamically insignificant". (IIRC, it was Ken Scott that I talked to.)

I discovered this phenomena on a customers RV-6 several years.
I re-drilled the horns to line up the elevators. We saw no noticeable difference in flying characteristics.

Right of passage

I think you'd have to be pretty good to get the counterbalance arms to align when the trailing edges are aligned, on your first try. What you have is a bit of a twist in the elevators. You can see it by running a piece of fishing line from one corner of the elevator to the opposite corner, do that in both directions and see what you have.

Regardless, I think the right technique is to align the trailing edges with a long straight edge and drill the control horns, let the counterbalance arms fall where they fall. 5/8 is getting up there, I think mine was 3/8. but if you could imagine an extreme case of misaligned elevators; the plane would want to corkscrew through the air.

You never park with the elevators level anyway so nobody will notice. See what vans says though about the 5/8.