April 29, 2016 – What a day this was! Myself and a helpful crew got the wing drilling done.

This had to be the warmest day of Spring so far this year, and I was feeling it by the time we were done.

I moved the fuselage and the wing cradle out into the driveway. We removed the flaps to help give access to the aft spar for drilling. We then slid the wings into position. It kinda looked sad with the wings there but without the wing bolts installed.

042916003 042916002

We ground the threads off four hardware store bolts, and put them into place.

042916001

Looks much better with some dihedral…

042916004

We did have to trim the ends of the aft spars, and the forward strap of the center section “forks” to get the wings straight.

050416007 050416008

We leveled the fuselage laterally and longitudinally, then hung four plumb bobs on the leading edges, then snapped a chalk line on the driveway. We lined up the inboard plumb bobs on the chalk line, then started working on getting the outboard ends perpendicular. Both wings had a very slight forward sweep.

042916006 042916007 042916008

We measured from the outboard aft corner of each wing back to the upper corner of the side skin at the aft-most bulkhead. Got 173 5/8″ on each side.

We then used a level and a 3″ block to measure level on each wing. Some minor adjustments were needed, but we got it dialed in.

042916010 042916009

I then got down into position at the aft spar to drill. I had made a nice wood block with a drill bushing in order to get a straight perpendicular hole. We realized that we couldn’t keep the spar clamped AND have the block in place. I decided to do it by hand. I started with a #30, then stepped up to #21, then used reamers to .191″, .250″, and finally .312″. And a lot of Boelube… The bolts slipped in great and were nice and straight. Those of you who know will think that the bolt is in backwards in the photo below. I just slipped the bolt in to test fit. I had to take everything back apart because I’m still in the garage.

Here’s the before and after at the aft spar:

042916005 042916019

And here’s the proud daddy:

042916018 042916017 042916016 042916015 042916014 042916013 042916012

Time: 24:00 (total man-hours)

1 Comments on “Drilled wing aft spars”

  1. Pingback: Wings On, Take 2…

Leave a Reply

Your email address will not be published. Required fields are marked *