Plans Question

On pg 30 of the RV4 plans, expanded section D-D, it shows a 1/8x1in spacer 2in long on the right side. Two questions: what is the spacer for and should it be on both sides?

Thanks in advance, Tom

Is there a "Typ" note at the part??

This is how draftsmen usually denote a part that is used in multiple places.

Spacer...

Tom... Yes there is one to made for each side. (x2)

.. It appears that these are the "shims" to raise/set the incidence on the stab. I just came in from working on my fuse, and studying the SAME drawing. Interesting timing that I just saw your msg on here.

Gregg

What Greg says. One each side,held in place by the same bolts that hold the front edge of the HS assembly in place. In due course you might want to make the shims thinner or thincker to decrease or increase the HS incidence.

Be warned that you need to be VERY careful when you drill these holes - there are edge distance requirements not only on the angle rivetted to the front of the HS assembly but also on the longeron and on the reinforcement angle. THere isn't much room for error.



Here's an RV-8 that I looked at recently - note that the mounting holes for the HS are WAY too far inboard. This aircraft has about 700 hours on it, including "vigorous" aerobatics. Miraculous that the tail hasn't come off and a testimony to Van's design - but defintely NOT the way to do it!

Gregg, thanks for the info. That's what I finally figured out but wanted to be sure.
Chris, good advise, I'll be extra careful when I drill that part.

Learn from that pic!

No problem Tom -

WOW - that picture is gnarly Chris.... and it seems the only acceptable repair is to replace BOTH main longerons. Maybe there's another way, but wow...

Thanks for sharing that.
Gregg

Make the wing and horizontal stab incidence the same. We did it on our -4 and it flies perfect.

Greg - the plane had also been ground-looped - needed replacement/repair of all 4 longerons!

It had been flown in this state - I was impressed that everything had stayed attached despite the "standard" of construction! I guess Vans added plenty of saafety factor.

Chris

acam37 said:

Make the wing and horizontal stab incidence the same. We did it on our -4 and it flies perfect.

Click to expand...

Not good advice.

Built per plans the RV-4 wing has a positive incidence ( I think 1.5 degrees, but not certain).

Starting out with 1.5 deg. positive on the H.S. could have a very negative effect on pitch stability.