When to drill HS

[PilotRPI]

The front spar of the HS has 4 x 3/16" holes for assembly with the fuselage. The plans, section A-A say "enlarge/drill 3/16 dia in assembly with fuselage." The directions on page 6-2 say "Drill/match-drill all the holes inboard of the HS-00006/HS-00005 rib attach points (See View A-A). ..."

Should I enlarge those holes now, before I rivet the front spar together, so that I may properly remove chips and debur? Seems like the way to go. Maybe the statement on drawing A-A means that the 3/16 holes are necessary for fuselage assembly later and not necessary wait till later to do it?

Thanks,

Jesse

[Steve Ashby]

I made that mistake. Much later in your build, you will drill the HS to the fuselage. You may find that holes drilled to final size do not line up well enough to provide the necessary edge distance for either the HS spar, the longerons, or both. Ask me how I know.
If I could do it over again, I would not drill ANY holes at this point and leave that later for the HS fitting process.

[bret]

Don't know if you read this thread yet http://www.vansairforce.com/communit...d.php?t=140972
but those outer holes are very important to get correctly located and get messed up often. look forward through the plans to get an idea of what and where theses -3 bolts must go through.

[pilotkms]

Listen to what Steve says in #2. No good reason to drill them now. Chips are inconsequential. Alignment is VERY IMPORTANT.

[PilotRPI]

The 4 holes I'm talking about go through the web of the spar, longitudinally through the aircraft. You are enlarging holes already prepunched in the spar, 710, and 714. I think the holes you may be referring to are drilled through the flanges of the spar, vertically on the plane.



The holes are the ones next to the center clecos.

[bret]

O......those will bolt to the VS bracket, you will have a more precise hole matchup when you open up the HS holes in one step with the VS bracket drilling. you will need to have the EMP installed on the fuse and the VS offset and vertical arrangement before that drilling.

[PilotRPI]

Cool. Thank you.