Oct 28, 2021     06-05 - Vertical Stabilizer Assembly - (7.1 hours)       Category: 6 Vertical Stab

Assemble
10/25/2021 – 1.8 hours
10/26/2021 – 2.0 hours
10/27/2021 – 1.9 hours
10/28/2021 – 1.4 hours
The vertical stabilizer final assembly starts by clecoing and riveting the ribs and front spar together. Riveting with the pneumatic squeezer appears to be the preferred approach at first, but the angles and access quickly rules that technique out. I turned to the rivet gun with a double-offset cupped rivet set, which worked very well. I had excellent visibility of the gun and bucking bar with the assembly secured to the work bench.

The riveted skeleton gets clecod in the vertical stabilizer skin, and then flush riveted together. Riveting starts at the intersection of the forward spar and center rib, and then continues up toward the tip and then down toward the root. It helps to have a long reach for this step because you have to hold the bucking bar without seeing it all the way to the front spar. I laid the vertical stabilizer on its side on top of a couple 2x4s wrapped in towels and clamped to the bench. That was the easiest way for me to reach inside to buck the rivets. The flush rivets along the spar and center rib came out well, with just a couple of very minor blemishes.

Riveting the vertical stabilizer skin continued with the top and bottom ribs. Those areas are easily accessible with the pneumatic squeezer. Six holes on each side of the bottom rib that will be used to attach the empennage fairing are not dimpled and should be taped off to avoid inadvertently riveting them. The main challenge are the forward-most holes in the tip rib due to the very tight space. I didn't have room for the thinnest squeezer set, so I fashioned a small steel cover for the hole in the 3” yoke to act as a flat squeezer surface. I could just barely fit that into the space to set those rivets.

The final step in the Vertical Stabilizer assembly is to rivet the rear spar into place. The pneumatic squeezer worked really well to rivet the skin to the spar flanges, and to rivet the spar to the tip rib. I switched to the rivet gun to buck the rivets from the spar to the bottom rib because access for the squeezer wasn't great. The finishing touch is 3 blind rivets to connect the spar to the center rib.
[3x Rivet Gun, 1/8” Cupped Double Offset Rivet Set, 1/8” Cupped Straight Rivet Set, Flat Rivet Set, Tungsten Bucking Bars, Pneumatic Squeezer, 3” Yoke, Flat Squeezer Set]

** Note: Sheet 10-05 specifies match-drilling and final-drilling several holes in the bottom of the Vertical Stabilizer rear spar, which will be used to attach the VS to the fuselage. The aft bulkhead (F-01412A/F-01412B) is used as a template to drill those holes. My aft bulkhead is already installed, which makes access to those holes very difficult. Rather than risk mis-drilling the holes and ruining both the new VS and the empennage, I decided to order a set of aft bulkheads to use as a template. I think I'll have much better luck with the accuracy of the CNC holes from Vans than trying to drill straight holes in a dark and confined space.

  Oct 25, 2021     06-04 - Vertical Spar Skin Preparation - (15.2 hours)       Category: 6 Vertical Stab

Initial Prep (Debur, Trim, Drill, and Cut)
10/14/2021 – 3.3 hours
10/15/2021 – 0.9 hours
The plans call for the entire vertical stabilizer assembly to be cleco'd together, and then to drill all the holes in the skin. This is a good opportunity to see how all the pieces fit together, and to ensure the preparation of the ribs and spars is adequate. The front is an especially tight fit. After clecoing the VS together, the front holes (left and right, top and bottom) are match-drilled from the skin to the top and bottom ribs. The rest of the holes (roughly 200+) are then final drilled from 3/32” to #40. I found the best method for me was to cleco every hole, and then remove the cleco and drill one at a time. It takes a little longer, but it ensures the best possible alignment between the skin and ribs/spars.
[Hole and Edge Deburring Tools, #40 Drill]

Final Prep (Dimple, Countersink, and Shape)
10/16/2021 – 2.3 hours
I used the 22” C-Frame and standard diameter dimple dies for most of the skin dimples. Access to the holes for the front spar are a little difficult to get to, but I found that a stip of duct tape over a rolled up towel on the exterior of the skin helped pull the skin out of the way for the opposite side dimples. I switched to the pneumatic squeezer for the holes along the top and bottom of the skin forward of the front spar, and went to the manual close quarter dimple die for the two forward holes on the top. The holes at the very top of the skin do not get dimpled at this time – they will be enlarged and dimpled when the fiberglass tip is installed. There are also six holes at the bottom that don't get dimpled (the rib beneath doesn't get dimpled either!) or riveted, but will be used later for the fiberglass tail fairing.
[22” C-Frame with #40 Standard Diameter Dimple Dies, Pneumatic Squeezer with #40 Reduced Diameter Dimple Die, Close Quarter Dimple Die, Blind Rivet Puller]

Prime
10/15/2021 – 3.3 hours
10/18/2021 – 1.5 hours
I started by scrubbing and scuffing all of the vertical stabilizer parts to prepare them for primer. I do this step before dimpling and countersinking because it is much easier to work with the smooth parts than tear up the Scotch Brite pads on the dimples. I'll go back to dimple and countersink before degreasing and priming the parts.
[Grey Scotch Brite Pads, Bon-Ami Cleanser, Dupli-Color Degreaser, Dupli-Color Self-Etching Automotive Primer (Green – Rattle Can)]

Assemble
10/21/2021 – 3.2 hours
10/25/2021 – 0.7 hours
The rear spar, doubler, and hinge brackets get riveted together to complete the rear spar preparation. I started with the AN426 rivets at by back-riveting the doubler, spar and lower hinge brackets. I clamped the parts to the back rivet plate as tightly as I could to get a nice flush finish on the forward side of the spar. Back riveting worked really well with the exception of the rivets closest to the 90 degree bend in the lower hinge brackets. There isn't enough room for the back rivet set in that area, so I switched to the pneumatic squeezer for those rivets. I also used the pneumatic squeezer for the remaining AN470 rivets in this section.
[Back Rivet Plate, Back Rivet Set, Pneumatic Squeezer, 1/8” Cupped Squeezer Set, Flat Squeezer Set]

  Oct 24, 2021     06-03 - Vertical Stabilizer Rear Spar Preparation - (6.2 hours)       Category: 6 Vertical Stab

Initial Prep (Debur, Trim, Drill, and Cut)
10/11/2021 – 0.9 hours
10/12/2021 – 1.6 hours
10/13/2021 – 1.2 hours
Deburring the rear spar doubler is pretty standard, but takes a little extra time because the doubler is a thick piece and the tooling marks take some additional effort to grind down. I used a flat file and curved file to reduce the tooling marks followed with 150 grit aluminum oxide sandpaper to smooth and debur the edges. I also used a small (1” diameter) Scotch Brite wheel in an electric drill to debur the large holes in the doubler.

The hinge brackets have #12 holes that are used to attach the rudder that get final-drilled at this point. I clamped each hinge bracket to the work bench to final drill each individual bracket. There are also several holes in the rear spar, doubler, and rudder hinge brackets that are final-drilled to #30 after all the parts are cleco'd together. I finished the drilling step by match-drilling two holes in the top bracket of the lower hinge attachment brackets. These final two holes take a little extra work because you are drilling through steel rather than thin aluminum. You definitely need a sharp drill bit, some drilling lubricant, and patience to drill these holes.

Preparation of the VS parts concluded by fluting the ribs, radiusing sharp edges of the nose and tip rib forward flanges, and final-drilling the rib-to-spar attach holes. I found that the nose rib holes are a little tough to get to with a standard drill and bit, so I used a 90 degree drill attachment for those holes. You could also use a long (12”) bit, but the angle attachment worked well for me.
[Hole and Edge Deburring Tools, Flat File, Round File, 1” Scotch Brite Wheel, 150 Grit Aluminum Oxide Sandpaper, #12 and #30 Drills, 90 Degree Drill Attachment, BoeLube]

Final Prep (Dimple, Countersink, and Shape)
10/11/2021 – 1.1 hours
10/16/2021 – 0.4 hours
10/17/2021 – 1.0 hours
The rear spar doubler is a relatively thick part and is prone to some bending during the manufacturing process. I removed the bend by clamping the doubler to my work bench and hammering out the bend with a rubber mallet. I sandwiched the doubler between the bench and a scrap 2x4 to hold the piece steady while I worked the bend out. I applied downward force to the free end of the part, and hit the part with light-to-medium force near the edge of the work bench. I then loosened the part, slid it to the next set of holes (about an inch), and repeated the process along the entire length of the doubler. I kept repeating this process until I managed to straighten out the part.

The flanges of the spar and ribs are dimpled after the holes are final drilled with the skin. The pneumatic squeezer with reduced-diameter dimple dies provided the best access to dimple most of the holes with very clean results. The two forward-most holes on the tip rib that were match drilled with the skin are too close together to access with the pneumatic squeezer, so I did those two dimples by hand with a close quarter dimple die and blind-rivet puller.

The final job in this step was dimpling the #30 holes in the rear spar and countersinking the corresponding holes in the spar doubler. The bottom section of the spar is flush-riveted on the forward side where it attaches to the aft fuselage.
[Rubber Mallet, Vise, Pneumatic Squeezer, #40 Reduced Diameter Dimple Die, #30 Dimple Die, Close Quarter Dimple Die, Blind Rivet Puller, #30 Countersink Cutter, Microstop Countersink Cage]

  Oct 21, 2021     06-02 - Vertical Stabilizer Front Spar Preparation - (2 hours)       Category: 6 Vertical Stab

Initial Prep (Debur, Trim, Drill, and Cut)
10/11/2021 – 0.8 hours
Assembly of the vertical stabilizer starts by preparing the front spar and doubler. The doubler has an additional function as a template to match-drill and trim the bottom of the front spar. I match-drilled the 3/32 (#40) and 1/8 holes in the doubler and spar, and then trimmed the bottom of the spar to the bottom edge of the doubler. I also removed the excess section of the doubler after completing the match drilling and spar trimming.
[#40 and 1/8 Drill, Band Saw, Flat File, Hole and Edge Deburring Tools]

Final Prep (Dimple, Countersink, and Shape)
10/11/2021 – 0.3 hours
10/16/21 – 0.2 hours
The bottom six holes in the front spar and doubler are dimpled with the flush side of the dimple on the aft side of the spar and doubler. The flanges of the spar don't get dimpled until after the holes are final drilled with the skin. The pneumatic squeezer with reduced-diameter dimple dies provided the best access to dimple the holes with very clean results.
[22” C-Frame with #40 Standard Diameter Dimple Die, Pneumatic Squeezer, #40 Reduced Diameter Dimple Die]

Assemble
10/21/2021 – 0.7 hours
I finished the front spar preparation by riveting the doubler to the forward side of the front spar. The manufactured head of the AN426 rivets (flush side) goes on the aft side of the spar, and I put the manufactured head of the AN470 rivets on the aft side as well. The pneumatic squeezer with the 3” yoke reaches all of the rivets pretty well.
[Pneumatic Squeezer, 3/32” Cupped Squeezer Set, Flat Squeezer Set]

  Oct 11, 2021     06-01 - Vertical Stabilizer Re-Do Category: 6 Vertical Stab

I described a critical error I made in an earlier section (10-28) where I mis-drilled the holes where the vertical stabilizer attaches to the aft fuselage. The short story is I didn't line up the drill correctly, and ended up with an unacceptable hole through the vertical stabilizer rear spar and doubler. Fortunately, I stopped drilling before I reached the aft bulkhead of the fuselage; which limited the damage to just the vertical stabilizer.

I consulted Van's about the error and the tech support team responded that I needed to replace the rear spar and doubler. That doesn't sound too bad until you recognize that the way to replace the rear spar is to disassemble the entire vertical stabilizer. I knew that the chances of successfully removing every rivet in the assembly without damaging other parts was very low, so I decided to re-build the vertical stabilizer with all new parts.

  Nov 27, 2020     Vertical Stabilizer Complete! (51.5 hours) - (4.3 hours)       Category: 6 Vertical Stab

The vertical stabilizer is finished! (for now) There were a couple of final challenges to complete this section of the build. First, I had to figure out how to rivet the front two holes in the skin to the tip rib. The combination of the angle and the tight space made it impossible to get my pneumatic squeezer in cleanly, and I did not have a bucking bar that would fit that space either. I tried to make a “thin” bucking bar out of a 1/8” x 3/4" x 48” strip of steel. That solution had potential, but did not lead to clean rivets on my practice piece. I then used the steel strip to replace the 1/4” flat set in the squeezer, and the additional 1/8” clearance was just enough to get the squeezer in to set the rivet.

I set the skin to rear spar rivets with the squeezer, and then turned my attention to the final rivets for the rear spar and ribs. The squeezer did a nice job on the two rivets on the tip rib, but I got sloppy with one of the rivets and had to drill it out and replace it. The universal head rivet is harder to drill out cleanly, but I manage to get it out without damaging or enlarging hole (whew!).

I could not find a good angle with the pneumatic squeezer c-yoke or longeron-yoke on the bottom rib to spar rivets, so I went to the rivet gun and tungsten bucking bar. The rivet gun worked great on those rivets! The final 3 rivets were blind rivets (pop-rivets) through the rear spar to the center rib. These were the first blind rivets on the project, and they seemed to get set without any issues.

Time to find a place to safely store the vertical stabilizer, and on to the rudder!

  Nov 25, 2020     Absolutely Riveting! - (4.2 hours)       Category: 6 Vertical Stab

It is finally time to get comfortable with the rivet gun, mushroom set, and bucking bar to set flush rivets in the skin of the vertical stabilizer. I started riveting the skin to the front spar at the intersection of the center rib with an AN426AD3-4 rivet. I then moved up the spar toward the tip and down the spar toward the root with AN426AD3-3.5 rivets. I then flipped the stabilizer over to do the other side.

A couple of hints:
1) Put something under the area you are working on to absorb the blow of the bucking bar if you accidentally drop it. I didn't' drop the bucking bar, but it tried to get away a couple of times. I put a folded towel under my hand just in case.

2) The rectangular tungsten bucking bar is fabulous and well worth the investment! It has plenty of mass to get the job done, but is compact and fits comfortably in your hand. I would have struggled to use a larger steel bucking bar in the confined space between the skins next to the forward spar.

This was a very time-consuming process as I learned how to hold the bucking bar square to the rivet without being able to see the bucking bar or shop head of the rivet. I also had to learn how to get into the tight area with the rivet gauge to inspect the rivets. These were all valuable lessons, and I was very surprised with how well most of the rivets turned out. I had to drill out one rivet that wasn't salvageable, and I had to go back to several rivets for a few additional taps to ensure they were set fully. I did make one small “smile” and a small ding, but overall it came out nicely. My left forearm was burning after a couple hours between the skins with the bucking bar.

I switched back to the pneumatic squeezer to rivet the skin to the op and bottom ribs. I actually had to re-do one of the squeezed rivets as well when the squeezer slipped off the center of the rivet and made a mess of the shop head. I'm comfortable drilling out bad rivets thanks to some practice removing rivets from the practice kit, and it was a quick job to remove the old rivet and install a new one. I can't get to the forward most rivets on the left and right sides of the tip rib, so those will have to stay cleco'd until I can talk to my local builder's guild and figure it out.

  Nov 24, 2020     Rear Spar and Vertical Stabilizer Skeleton Rivets - (4.5 hours)       Category: 6 Vertical Stab

Riveting continued with the rear spar. I did all the rivets with the pneumatic squeezer, and I was very happy with the results. This step requires a good understanding of all the notes and rivet schedule details in the plans. For example, several holes are left open (covered with tape to prevent accidental riveting), and the AN70 rivets were installed with the manufactured head on the aft surface (normally the manufactured head is on the side with the thinner material).

With the rear spar complete, I moved on to the final assembly of the forward spar and ribs. I cleco'd the spar and ribs together, and managed to set the rivets for the center rib and tip rib with the pneumatic squeezer. Unfortunately, the squeezer will not work for the root rib and nose rib, so I had to get out the rivet gun and bucking bar for the first time. I did a few practice rivets on a scrap piece of aluminum, and then moved on to the actually vertical spar assembly. The 1/8” cupped set and tungsten bucking bar worked perfectly on the AN470 rivets, and I could breathe a huge sigh of relief knowing that my first 3 bucked rivets turned out great!

  Nov 22, 2020     First Actual Rivets! - (1.3 hours)       Category: 6 Vertical Stab

I reached another milestone today – the first actual rivet installed! I riveted the vertical stabilizer forward spar doubler to the forward spar. This step included 6 AN426 rivets set flush on the aft side of the spar and 4 AN470 rivets also set with the manufactured head on the aft side of the spar. I used the pneumatic squeezer to install the rivets with good results.

I finished the session by clecoing the rear spar, rear spar doubler, and hinge brackets together for the next riveting step.

  Nov 17, 2020     Skin and Rear Spar Dimpling / Countersinking - (3.1 hours)       Category: 6 Vertical Stab

I set up the c-frame dimpler with adjacent level surfaces to dimple the vertical stabilizer skin. The c-frame did a great job on the dimples. There were a couple of dimples near the bend in the vertical stabilizer skin that I could not get to with the c-frame, so I went to my pneumatic squeezer for those. The dimple quality between the c-frame and pneumatic squeezer is very similar, but I think the c-frame dimples are slightly better / crisper.

With the skin dimpling done, I turned my attention to the final dimples in the rear spar and corresponding countersinks in the spar doubler. I used the pneumatic squeezer and the 1/8th dimple die set for the #30 holes in the rear spar. There are 21 holes at the bottom of the spar that need to be dimpled for AN426AD4 rivets.

The last item on today's agenda was machine countersinking the holes in the rear spar doubler that correspond to the dimples I made in the rear spar. I set up the microstop countersink cage for a countersink depth that sets the rivet exactly flush with the material. This, however, is not deep enough to receive the dimple from the rear spar and still lie flat. I adjusted the countersink another 0.005” deeper, which still wasn't quite enough. An additional two clicks deeper, for a total of 0.007” deeper than flush for the rivet seemed to be the right adjustment to just completely accept the rear spar dimple cleanly.

All vertical spar parts are now ready for final cleaning, primer, and assembly!

  Nov 16, 2020     Dimpling Rib Forward Flange - (0.4 hour) Category: 6 Vertical Stab

Successfully dimpled the two forward holes in the tip rib flange using a close-quarters dimple die set, hand rivet tool, and 4D nails from the hardware store for mandrels. The set up wasn't perfect, but did an adequate job on the dimples. It is definitely not ideal for large-scale dimpling!

  Nov 12, 2020     Final Deburring and Dimpling - (6.9 hours) Category: 6 Vertical Stab

Deburring is complete, and all vertical stabilizer pieces have been scuffed prior to priming. Final preparation for priming will occur within 2 hours of actually applying the primer to minimize oxidation between cleaning and priming.

Dimpling the #40 holes in the flanges of the front and rear spars as well as the ribs is nearly complete. The two forward-most holes in the tip rib need a close-quarters dimple die to make the dimple. I have a dimple die set to be used with hand riviet (pop rivet) tool, but the nails that came with die set to be used as mandrels for the hand rivet tool are too long and too thick to use for these holes. I'll have to see if the hardware store has nails I can use as a replacement.

  Nov 11, 2020     First Mistake and Deburring - (8 hours)       Category: 6 Vertical Stab

I continued deburring yesterday and today. The holes inside the flanges took extra time to debur because my deburring tool won't fit in that space. After finishing all the holes I started with deburring edges. There's still some more work to do there, but I'm getting through it.

I need to send a HUGE thank you to my tech counselor for his assistance with my first mistake. After I disassembled the rear spar, I noticed two of the three holes for the center rib attachment were a complete mess. After panicking for about 20 minutes, I considered trying to make a doubler to go over the area and sandwich the bad holes between the doubler on the back of the spar and the one I planned to make on the front. I reached out to my tech counselor for his advice, and he had a much simpler solution for me.

“drill two new holes providing at least one hole diameter edge distance from existing and rivet then clean up the bad holes and rivet them too. … take a longer rivet and slightly squeeze it to shorten it and make it a larger diameter then insert and complete rivet. If match hole drilling, this issue is usually caused by only clecoing one hole. Cleco two, drill, move cleco and drill.“

I took the advice of my tech counselor, and I'm very pleased with how it turned out! Thank you!

  Nov 08, 2020     Skin Drilling and Deburring - (4.5 hours) Category: 6 Vertical Stab

The vertical stabilizer skin has 206 holes that need to be drilled to final size plus 4 more that need to be match-drilled into the forward flange areas of the tip and nose ribs. The holes in the skin are already final size, which made the final-size drilling of the substructure go quickly. When all the drilling was complete, everything gets disassembled to enable deburring of the holes and edges and prep for primer. I deburred the holes in the skin and decided to call it a day.

I will continue deburring holes in the ribs and spars tomorrow, but the edges will have to wait a few days until I get a couple more deburring accessories. It's also time to make some decisions about priming – like where I'm going to do it!

  Nov 07, 2020     Skin and Skeleton Cleco'd Together - (3.4 hours)       Category: 6 Vertical Stab

I double-checked the flange angles of the tip rib to unsure it matched the taper of the spars, and then I radiused the front corners of the nose and tip ribs to remove the sharp edges and help them fit easily into the vertical stabilizer skin. With the final adjustments to the flanges complete, the entire vertical stabilizer skeleton was cleco'd together for the first time. I then cleco'd the skin into place to prepare for final drilling. It was very exciting to see an assembled part that is an identifiable piece of an airplane!

  Nov 05, 2020     Fluting Lessons - (2.0 hours) Category: 6 Vertical Stab

I visited another nearby RV-14 builder for a quick lesson on fluting rib flanges. I had never tried that before, and wanted to make sure I was on the right path. He uses the method shown in this video:
https://www.youtube.com/watch?v=pIvFpVV6kIQ&feature=youtu.be

After a couple of hours in my neighbor's shop, I returned home with straight ribs for the vertical stabilizer. One additional note – my neighbor recommended scuffing the flanges before fluting if you're planning to prime. It's easier to do the initial scuff while the flange is flat than a fluted flange.

  Nov 04, 2020     Drill Lower Hinge Bracket Corner Holes - (0.3 hour) Category: 6 Vertical Stab

The only task for today was to match drill the upper hinge bracket of the lower rudder attach point. It was just 2 additional holes in the hinge bracket, so it didn't take very long.

  Nov 03, 2020     First Dimples - (1.8 hours)       Category: 6 Vertical Stab

After one more quick check of the Section 6 and 11 plans, I dimpled the six “Dimple Flush Aft” holes in the forward spar and spar doubler. The language in the plans is a little foreign at first, but it is precise and makes sense when you think through it.

The work on the aft spar assembly continued by final drilling the rudder attach holes in the six hinge brackets; clecoing the rear spar, spar doubler and hinge brackets together; and final drilling the hole pattern in the hinge brackets and spar doubler into the spar.

  Nov 02, 2020     Front Spar Adjustments and Rear Spar Begins - (1.9 hours)       Category: 6 Vertical Stab

I continued small adjustments to the cut I made in the forward spar, and radiused the new flange corners. I started the corners with a flat file, and then went to a 6” Scotchbrite cut and polish wheel on the bench grinder to finish the radius. I deburred the new holes in the spar and the doubler as well as the doubler and spar edges.

I moved on to the rear spar starting with identifying and marking the parts for the rear spar assembly. The rear spar doubler is a relatively thick piece of aluminum, and I learned it tends to bend during the manufacturing process. Mine had about a 3/4" bow in it that needed to be straightened. The General Information section of the plans, paragraph 5.13, shows a technique to straighten thick aluminum parts with a vise and a hammer. It is officially time to go into cave-man building mode! After about an hour of “whangs”, the doubler lay flat on the table – the 3/4" bow is down to less than 1/32” at the very end of the piece.

  Nov 01, 2020     "Bending Metal" -- Day 1! - (1.5 hours)       Category: 6 Vertical Stab

Today was a milestone – the first day actually working on airplane parts! It was a little intimidating since you start off by drilling holes in your brand new vertical stabilizer forward spar followed by cutting a chunk of the spar off. The drilling and cutting seemed to go well. I used a drill block to help me drill perpendicular to the material, which is a good technique for me since I don't quite have the sight picture to do it freehand. I made the cut with a simple hacksaw followed by a flat file to fine-tune the cut.

  Oct 30, 2020     Work Begins! - (2 hours)       Category: 6 Vertical Stab

It is time to start working on the first major component of the airplane – the vertical stabilizer. The vertical stabilizer consists of 2 spars, 4 ribs, a couple of spar doublers, a handful of hinge brackets, and a single-piece skin. Compared to other components later in the build, this one is relatively simple. It is, however, the first step in the build; which adds some anxiety into the process.

A mistake on step one would be a huge setback, so I took time to study the plans to minimize the potential for a rookie error. The plans for this section contain a lot of information that isn't obvious the first time you flip through the pages. There is a lot of new language to learn (dimple flush aft???, match drill 1/4 the 1/8 hole???) as well as getting comfortable with the drawings. (BTW – the new language issues were solved by looking forward in the plans to section 11 to see how the vertical spar mated to the rest of the empennage).