Chapter 9 – The Wings (Main)

The wing kit arrived today. One long box & a shorter flat box. This time the crating was plywood (as opposed to the cardboard used for the empennage kit. One corner of the long crate had some slight damage. There was no problem with the parts. Maybe I can start inventorying the stuff this weekend.

Aug 13, 2005 – Started to inventory parts (2 hours today – xx Total)

It took a few minutes but I was able to pull the cover plywood off both crates using a claw hammer and a gooseneck pry bar. The first thing I did was unwrap most of the parts from the paper. After they were opened, I started inventorying all the fasteners and miscellaneous small parts in the “big bag”. Everything was accounted for … but I had one small extra bag (not included) in the fastener list. However, I did find it called out in the main packing list (I think it was for the lens cover fasters).

Fig 9-1 Fig 9-2

Aug 20, 2005 – Completed inventory (3 hours today – xx Total)

Continuing to count and inventory parts…. There sure is a lot of stuff (and packing materials) crammed into those two boxes.

Fig 9-3 Fig 9-4

Nov 7, 2005 – Started Main Wing Jig (0.5 hours today, xx Total)

It’s been a long time for me to get started on the wings. I had spent quite a bit of time building a new trim tab (remember I dropped it on the trailing edge just as I was doing the final bend ... and after settling down - decided to make a new one using my past experience and “lessons learned”). In addition, I also spent a lot of time on line researching how others decided to countersink the center mounting holes in the spar for the fuel tanks. It seems there are two major approaches to working the spar – Van’s (which uses the nut pates to guide the center counter sink) or Dan C’s jig method (which uses a fabricated jig clamped to the spar to support and center the countersink tool). It’s going to be more work – but I decided to go with the jig. I used a peice of 11/2 x 1/8 aluminum angle. Three sets of hoels are required… one for the main holes paralle; ot the web and two on the outboard end that are angled. The major trick is to make sure the main center hole is PERECTLY CENTERED over the parent screw hole in the spar.

Nov 8, 2005 – Started Main Spar – CS Jigs (1.5 hours today, xx Total)

Here’s a pic of the first step where the jig is clecoed in place… In case you are wondering, the blue tape is to keep machined aluminum chips from falling between the riveted parts (better to prevent this than have to fix it!!!)

Fig 9-5

Anyway, after the jig is clecoed in place, the next step is to clamp the part on the outside. Then the clecos are removed and you’re ready to drill (you can’t drill the hole if the clecos are still there!!).

Fig 9-6

When all is done – you have a nice.. centered.. round countersunk hole that matches the fuel tank!

Fig 9-7

Nov 11, 2005 – Completed Spar - Tank Machining (10.5 hours today, xx Total)

Had a great day today – but I think my arms are going to pay the price tomorrow. It’s Veteran’s day – and I was able to spend most of my time in the shop. This meant 10 hours of drilling, countersinking – and clecoing!! By the end of the day I had drilled and countersunk all fuel tank attach holes in the spars. Each center hole needed me to attach and remove clecos up to 8 times!! But… I took my time and I think they came out great. It may be harder and longer – but using the jig really made a nice job! Here are a few pics…

Fig 9-8

And some more shots (you can see my progress if you look closely)…

Fig 9-9

Like I said before – I am happy with the results (but not the picture). The holes came out accurate, fairly round and centered.

Fig 9-10

One of the things not mentioned in Van’s directions but I thought was important was to make sure I deburred the back side of all holes in the spar cap. I was especially concerned about the sharp “knife edge” that resulted from the deep counter bore of the center hole. It didn’t take much time, and I’m feeling much more comfortable knowing I took the extra step.

I wanted to prime the machined holes that I make in the spar caps – but decided I would counter sink the holes for the access panel holes first. This meant finding the parts – and then prepping them à i.e. removing the vinyl, smoothing the edges, drilling the front holes to size (but NOT the others since they are a different size!) , deburring the drilled holes, and finally dimpling the forward holes.

Fig 9-11

Now that I had the access panels dimpled – I was able to set the microstop counter bore tool to the right depth.

Fig 9-12

By now it was late – and I had made serious progress. So, I decided to quit before I made a major mistake. Like I said at the beginning – it was a good day!!

Nov 12 - 14, 2005 – Finished Spar Prep & Started Riveting (16 hours today, xx total).

This weekend I finished the spar prep – and completed riveting all the plate nuts in place (both the fuel tanks and access panels) and then spot primed the spars. Unfortunately I got behind in keeping the log – so rather than go into a bunch of words I’ll let these pictures tell the tale….

Fig 9-13

Fig 9-14

Fig 9-15

Fig 9-16

Nov 16 – Dec 31, 2006 Started to Prep / Debur Ribs (4 hours totay, xx Total)

I’m still behind in the maintaining the log and between vacation planning, shopping, company & private parties - not too much building was accomplished between Thanksgiving and Christmas. However, I did manage to pull out some of the wing ribs and started to debur them.

I originally used the edge deburring tool to touch up the flanges, but that didn’t seem to work very well. I also used a Scotchbrite wheel in my drill press for the inside of the rib lightening holes. Again – I wasn’t very pleased with the results. Then just before Christmas I visited Dad & Mom up in Canada (you may remember that Dad built an RV-4 and Mom built an RV-9A). I asked them what they used and Dad recommended 180-200 grit emery cloth for a first path and then scotchbrite pads for the final pass. I went home and this worked great. But there are a LOT of ribs so I tried to do a couple of them whenever I had a little free time. Each of the main wing ribs takes about 20 – 30 minutes.

January 10, 2006 – More ribs (1.5 hours today, xx Total)

What can I say – More ribs… This is going to be tedious. The good news is that I’m starting to develop a routine so the time for each rib is beginning to drop. I think I’m also getting a little better at it.

Here’s what I do – first I take about 5-6” of 180 grit emery cloth and get the major burs off the formed flanges. Then I use the same emery cloth on the interior lightening holes. By now the cloth is a little less stiff so it can be used to touch up the notches for the stiffener and any other flange edges/relief holes. After all the edges have been “sanded” I go back with a heavy duty scotchbrite pad and redo everything I just covered. When it’s finished – everything is clean, smooth even feels a little “Soft”. I’m not sure but I think the gently rounded edges give the illusion of being soft. Each rib takes one section of emery cloth and a 1 ½” x 4” strip of scotchbrite.

January 13, 2006 – And Still More Ribs (2 hours today, xx Total)

Oh yeah….. more ribs.

January 14, 2006 – Even More Ribs (3 hours today, xx Total)

Almost there!

January 15, 2006 – Ribs? No Thanks, I’m Done! (2 ½ hours today, xx Total)

Ta Da!! All done – well at least for the main ribs. I still have all the nose ribs & fuel tank ribs to go. The next step is to go in and flute the edges of the ribs to get the holes to line up with the skin. I think I’m going to push that off for a little while though – I’m sick & tired of ribs!

Jan 20, 2006 – Completed Tiedowns (4 hours today, xx Total)

Had another good day today. It started off by going out to Kelly Johnson’s place and with a few friends helping him buck rivets on his fuselage and moving cleco’s (I was on cleco duty). Then, when I came back home - I went right to work my project. The tiedowns already had the 3/8” x 16 holes tapped on one end - so the next step was to get the platenuts attached. I carefully laid out the upper mounting hole and then drilled the holes for the bell crank brackets and main attach points.

Fig 9-17 Fig 9-18

In order to get the platenuts aligned – I used a simple jig (based on the fuel tank mounting jigs). The center hole was aligned by inserting a 3/16 inch bolt and then using a few parallel lines on the jig, I eyeballed the fixture to make the nuts relatively straight. Parts were clamped in place with cleco’s and the rivet holes were drilled on the drill press.

Fig 9-19 Fig 9-20

I deburred the holes, countersunk the rivet holes, primed the parts & installed the platenuts. It went as easy as it sounds. Oh, one obvious point – don’t forget to mark the left and right sides!

Fig 9-21 Fig 9-22

After the parts were completed – it was a simple task to bolt them to the main wing spar.

Fig 9-23

Since I had made pretty good progress – and didn’t want to mess up – I pulled out the parts for the rear spar, and then decided to call it a day.

Jan 21, 2006 – Started Rear Spar (3 hours today, xx Total)

I still did not want to look at those ribs yet, so I pulled out the parts to the rear spar and reviewed the drawings and plans. The rear spar assembly looked similar to the HS spar so I felt pretty comfortable with that. However – there is a difference – several of the holes need to be dimpled BEFORE riveting the doubler plates. Here is another area where Van’s directions are not as clear as they were on the tail kit. In addition to sections of the flange needing to be dimpled – there were a few holes on the end of the spar web that also need to be dimpled.

After thinking this through for a while, it was time to get to work… First step – pull out the parts.

Fig 9-24

Jan xx – Prepped Rear Spar Parts (xx total, xx Total)

Starting fresh on a new day, I removed the protective vinyl on the outside edges of the main spars. This would allow me to drill, debur and dimple as required.

Fig 9-25 Fig 9-26

Next I found the center doubler plates and clamped them into position. It took a few minutes to find the right dimension on the drawings – but after looking for awhile I found it. When clamping the doubler plate – I first joined the flanges together (so the plate fit tight against the spar corner) and then clamped the webs together. All holes were match drilled.

Next I marked the hole for the aileron bellcrank and used my unibit (in two separate locations) to get most of the material out. Remember, if you don’t want your work to move – then CLAMP-it! After the holes were rough cut to the approximate size, I rejoined the parts with clecos and used a round file to match the profile. It was not difficult to get a very close fit. I finished the prep using emery cloth and then the scotchbrite pad.

Fig 9-27 Fig 9-28

The spars and bellcrank doubler plates were drilled, deburred, and set aside for priming.

Jan xx, 2006 (xx total, XX total)

Today was going to be an easy day, no pressure – but I did want to get the doublers ready for assembly. Hmmm, not quite as easy as I thought it would be. The large “Vee” plates were smoothed using a 1” belt sander and followed up with emery cloth. Then I toughed up the outside edges with the scotchbrite wheel and finally polished the edges with a scotchbrite pad. The short doubler plates were done the same way – except I could get all around the outside edges. I assembled the spars – Clecoing every other hole and then match drilled the entire assembly. Next came the thinking part. Not all plates were to be riveted. Nor were all rivets the same. This was a little confusing and I finally took my best guess at it – marked the holes and verified it by going to the web (what a great resource!!).

After the boring but necessary clamping, drilling, countersinking, and deburring, I removed the remaining vynal and primed the parts.

Fig 9-29 Fig 9-30

Jan xx, 2006 Started to Rivet the Rear Spar (3 hours today, xx Total)

Well, now that the parts were prepped and ready to be assembled for the final time – I might as get started.

Fig 9-31

Fig 9-32 Fig 9-33

Jan xx, 2006 - xx

Fig 9-34

Fig 9-35

Fig 9-36

Feb xx, 2006 – Completed Fluting Ribs

Fig 9-37 Fig 9-38

Fig 9-39

Feb xx, 2006 – Assembled Wing Skeleton (just 4 kicks)

Fig 9-40 Fig 9-41

Feb xx, 2006 – Deburred & Straightened leading edge Ribs (2 hours today, xx total)

No pics – just more boring detail work… but now I’m done and ready to move on.

Feb 25, 2006 – Completed Wing Jig (8 hours today, xx total)

Wow, it was a great day! After almost a month of playing around with parts, it seems like I finally made some progress.

Fig 9-42

Fig 9-43 Fig 9-44

Check out the mid span jacks being glued & clamped in Figure 9-43. They are a little overkill – but should work great!

Fig 9- 45

Fig 9-46 Fig 9-47

You can notice in Figures 9-46 and 9-47 that I had the end rib flush against the jig angle. After reviewing the drawings I saw that this will not give me enough room for the skin overhang (that connects to the wing tips). Therefore, I’m going to have to replace the small aluminum angle with a wider piece. No problem – I have lots of room to slide it inboard –so this means I just need to take an extra step!

Feb 28, 2006 Drilled & deburred Right Wing Ribs to Spar (1.5 hours today, xx total)

After I got everything set up moved the right wing skeleton onto the workbench and drilled the rib-to spar holes. Disassembled everything and deburred the parts. I also dimpled the rear end of the outboard rib.

March 3, 2006 Re-attached the Spar to Frame (1 hour today, xx Total)

Who says you can’t get something for nothing? Today I dropped by a local structural metal distributor to pick up a small offcut angle to replace the ones supporting the outboard spar tips (the original angle was too short and would not allow the skin to fit on the outboard end). I found a great piece of aluminum angle 2 ½” x 4” about 14” long. It was the perfect size... but even better -> they just gave it to me! I know I’ll be back there later when I need some more supplies.

Within just an hour or so of work, I had the angle cut, drilled, and deburred. The two holes for the ribs were drilled and the spar clecoed to the end rib assembly. Julie helped me get it onto the frame and now I’m almost ready to start riveting the main skeleton. You can see the extra clearance I needed in the following pics…

Fig 9-48 Fig 9-49

March 4, 2006 Where to Run the Wing Conduit??

I spent a little time going over the plans and reading the manual trying to decide where to run the wing conduit. I had already received 50’ of the 5/8” corrugated stuff from Van’s. My biggest concern was I didn’t want to weaken the rib, but also wanted a clean run that did not interfere with the bell crank, aileron assembly, nor the inspection panels on the lower skin. I looked on Van’s site and he recommended a couple of areas. I also searched the web and found a few more ideas. Right now I’m leaning toward the lower mid section of the rib as recommended by Van’s. However, my other preference is up near the top front surface of the main spar.

March 7, 2006 Selected Conduit Location

I spoke with dad and others on the wing conduit wiring location. After a few discussions and some email exchanges, I decided to go with the Van’s recommended location -> behind the first lightning hole on the lower edge.

March 19, 2006 – Final Rib Prep (6 hours today, xx Total)

After a week-long business trip, and with Dad finally in the area (he was teaching an EAA Sheet Metal Assembly class about 1 hour away in Watsonville, CA), we started the final prep of the ribs. For those interested – Mom was also around, but she went down to King City, CA to take 3 solid days of aerobatic training session at Sean Tucker’s Aerobatic school (drool!!).

Anyway, I made a simple jig out of ¼” thick wood that butted against the front & bottom of the ribs. Then using one rib as the master, I laid out where the wing wiring hole should go. By clamping the wood in place and then drilling through the rib – I had a master template that I then used on all the ribs. In 20/20 hindsight – it would have been better to use the back of the rib & the bottom for the jig – since some of the ribs are a little shorter than others (because of the front spar doubler).

I piloted all holes (using the jig) and then bored the holes to ¾” with a unibit. However, before drilling the holes with a unibit – I took a scrap 2x4 and piloted the unitbit hole in it (creating a upside down cone hole). I finished the unibit support by drilling a ¼” hole all the way through the stud at the base (i.e. bottom “tip”) of the cone to allow drilling chips to fall out. The 2x4 was clamped on the drill press and all ribs were drilled.

I previously had a question about the number of wires I needed, and after a little investigating I think I can get them all in one 5/8” conduit.

Note: I plan to use Whelen lights with the 3 remote power supplies to avoid running high voltage lines throughout the plane.

All ribs were primed and then clecoed to the front spars and each wing skeleton was put on the stand for same keeping.

Fig 9-50 Fig 5-51

Fig 9-52

March 20, 2006 Riveted Wing Skeletons (6 hours today, xx Total)

With Dad’s help, we had another day of really good progress. I had Dad confirm both the placement, and selection of ribs on the main spar (he said I had them right). I’m not too proud to ask, and an extra set of eyes is always a good idea. Then, we decided to “bite the bullet” and start riveting the ribs to the main spar. I took out a couple of thin camping mattresses and taped them to both work benches. This made a great working surface. It supported the skeleton and was comfortable to lean on.

Fig 9-53

Next, following Van’s recommendation we bucked the main ribs to front spar rivets – putting the factory head on the rib side (this gives more surface area on the thinner material, therefore maximizing strength and minimizing distortion). In all cases we went with one rivet size shorter than the directions called out. This resulted in a PERFECT set. Dad bucked & I drove. I started with my offset driver since I didn’t want to bend the ribs out of the way. However, it seemed awkward and a lot more work that it should have been so I moved to the straight set. This was a lot easier to control – and even though I had to bend the ribs a little sideways - we did not have any problems.

It’s probably obvious, but we worked our way from outboard end to inboard end so it was easy to get access to the final ribs that are close to each other (the ones under the doubler plate). We worked inboard and don’t cleco the final ribs until ready to rivet.

In order to avoid damaging the parts - we put tape on the bucking bar and the forward side of the main spar where the reinforcing straps were close to the outside rib rivets.

Fig 9-54

We finished the day by hand squeezing the rivets that joined the ribs to the rear spar. Again the parts were put back on the wing stand for safe keeping. I am a little relieved!! We got all the structural joints completed without any major problems. However, I must admit that I did feel a little pressure toward the end of the day to get the major structural work done. It took a few seconds for me to understand what was going on – and then slow us down a bit. Remember, this is not a race… and when I’m done – this is something that I will be FLYING!!

Anyway, I’ll get off my soapbox with one last comment -> Look Ma – NO CLECO’s!!!

Fig 9-55

March 22, 2006 Started Skin on Right Wing (5 hours today, xx Total)

Today was another good day of progress. We pulled out the Right wing skins, marked & predrilled selected holes in the doubler plates and then started to put the skins on the right side.

I decided to tape the doubler plate to the top skin before drilling the parts and kept the tape in place while clecoing the top skin/doubler to the skeleton. This ensured tha the skins remained aligned. About this time, Dad recommended we put the stringers in, so we took a slight detour and prepped these (i.e. cut to length, deburred, and installed). Actually, it didn’t go quite as easy as that. I cut the stringers to length, but after the initial fit-up we saw the outboard stringer was just a little bit too long, so I marked it and cut it back a little bit later.

After we finished the stringers we put on the right top wing skin/doublers. I am very please to say that by taking the extra time to get the ribs as straight as I could – the right wing skins fit perfectly with almost no adjustments to the ribs!

Fig 9-56 Fig 9-57

…. And one final pic before we called it a night….

Fig 9-58

March 25, 2006 Continued Skinning main Wings (6.5 hours today, xx Total)

We continued to work on the wings. – clecoing, drilling, un-clecoing, deburring, and dimpling. This is where the dimpling table really came in handy. We were able to get the doubler plate done without any problems. Note – I started with the doubler plate because even if I messed up – it would not be visible from the outside. In any case, no problems. We continued the work on the lower skins. Here is a picture after drilling, but before deburring.

Fig 9-59

As we worked, both the top and bottom skins were drilled, then the vinyl strips were removed and the holes deburred and dimpled. I had a couple of old closed film camper mattresses that made excellent work bench surfaces for the deburring process. This minimized any scratches and with the help of a foxtail brush, kept the work area clean.

Fig 9-60

After the skins were prepped, I needed to go back and machine (i.e. countersink) the main spar where the skins would be attached. This was easy to do while the skeleton was still in the wing jig. I decided to deviate from Van’s recommendation – and made the countersink to the same depth as the rivet – by adding just a few more “clicks” so the skin would fit tight. I did NOT machine too far so the bottom of the CS went through the far side of the spar.;

Fig 9-61

While machining the countersinks for the main skin – I also took the time to cut the holes for the Leading Edge skins…

Fig 9-62

Fig 9-63

Oh, I almost forgot – there is a small note in the middle of the plans that tell you not to dimple a few of the holes on the inboard skin – since these will be used to attach the wing fairings. I remember reading this, highlighting it on the plans – and then circling the holes with a red marker so that I would not make a mistake….

Fig 9-64