Hold up. What’s that red stuff and why is it everywhere? I had finally made it to the hangar and was excitedly looking over my recently completed brake project. Unfortunately, the brakes were leaking and hydraulic fluid was coating the floor of N2165U. There goes my fuel project. Time to troubleshoot this.

I grabbed a few wrenches, towels, a flashlight and a beer from the fridge and got to work. It was a classic project rule. This is why we often think we are 90% of the way done, when really, we have 90% to go. Unforeseen issues come up, we must deal with them and it takes time. It’s half the fun, but it also gets frustrating when you’re trying to get ready for Oshkosh.

It seemed like all the fittings were secure. We had tightened and torque sealed them so we would know if anything came loose. However, as I looked closer, two of the fittings were leaking. They weren’t tight enough! Phew, an easy fix.

Fuel Lines

After finishing up the brakes, mentor and building buddy Stan and I started working on the fuel lines. I had ordered the raw materials for the fuel lines—specifically 3003-0 tube in ¼- and ⅜-inch OD—as well as a gascolator mounting flange, replacement gasket and a replacement screen for the gascolator strainer. The original fuel lines worked, but they were old and had small dents. Stan and I also wanted to bend them to be closer to the floor and near the sides of the airplane so that they would be farther out of the way of people’s feet.

We easily removed the old fuel lines and started by measuring for the new ones. Stan showed me how to cut them properly with a tubing cutter. After setting the tube in the cutter and lining up the blade, you simply start moving the cutter around the tube in a circle, tightening it slowly until it cuts through. Stan also showed me how to bend the lines with a bending tool to make a perfect 90° angle. It was especially tricky to bend them just the right way. Ideally, you want to keep fuel lines as straight as possible, so the fewer bends the better. But it’s a compromise; they need to go where they need to go.

After a few hours of bending, we started attaching the fittings and Stan showed me how to use a flaring tool. I flared one end with a flaring tool, then slid the sleeve and B nut on. (Remember to do this in reverse order for the other end of the line!) From there, I worked the fuel lines into their positions and wrapped a rubber bushing around one of them so it wouldn’t scrape against the metal piece in the center that holds the fuel selector. One fuel line done! Then I repeated it with the other fuel line, eventually getting the lines between the left tank and the fuel selector and then the fuel selector to the gascolator finished. I took a break after that, deciding I’d tackle the right side down the road.

More Baffling

Baffling was a much longer and more complicated project than anticipated. After working on it on and off for many months, with more cutting, puzzling, deburring and painting, all of those janky metal pieces were finally coming together. Kerry Richburg prefers specific fancy shears to cut the metal, so he gave them to Stan who then showed me how to use them. We fitted the pieces together to ensure they had been built correctly. After determining they matched, we scuffed them up with Scotch-Brite and spray-painted them white. Zach came by to help work on the baffling and fasten it to the engine. Once fastened, we could properly fit the upper and lower cowling.

Fitting the lower cowling proved to be easy, while the upper part was a bit more difficult. If the baffling was too tall, then it would cut into the cowling. If the baffling was too short, then the air wouldn’t end up getting properly directed through the cylinders. Our main problem was that the baffling was too tall. Stan, Kerry and I identified the places where the baffling was hitting the cowling. Starting with Kerry’s fancy shears, we simply drew a line where we thought it was hitting and cut straight across. As the problem areas started getting more specific, we started grinding them down using an air grinder. We were able to identify if areas of the baffling were still hitting the cowling by setting the upper cowling on top, lining up the piano hinges like we would if we were putting it on and then tapping on the problem areas. The cowling is fiberglass so it’s somewhat flexible, so if it was hitting something hard underneath (the baffling), then we would feel it underneath because there would be little to no give in the cowling.

I worked on the baffling project on my own one evening after work and made the mistake of not bringing shoes! I had my Birkenstocks but that was it! Unfortunately, when you grind metal in sandals, you end up with metal between your toes. I spent the end of the session picking metal pieces out of my shoes and my own feet but was happy that the project was getting done.

After getting the metal baffling low enough to not hit the upper cowl, I fastened the upper and lower cowlings together. Thanks to Kerry and Hal’s hard work from early on, the wires actually fit through the piano hinges without a problem. I’m so grateful for them, their skills and their thoroughness!

Next, we created doublers to strengthen the baffling and protect the rubber, then attached nut plates to them. The plan was to put the rubber in between the doubler and the baffling to maximize surface tension so it would stay flat, not get all wrinkly and let air through. Stan wanted to screw the rubber in instead of riveting it so that it would be removable if needed and we wouldn’t have to deal with so many rivets. We riveted nut plates to aluminum strips that we measured, cut and deburred ourselves. Then, we fastened them with screws onto the baffling.

Transition Fairings: Kerry the Fiberglass Master’s Project

My plane never had transition fairings between the gear legs and the fuselage so Kerry was determined to make some. He and Hal made molds of Hal’s from his RV-6 next door. Once fitting the fairing to see if it would work, he analyzed it carefully and then filled it with modeling clay that looks like Play-Doh. He let it set by putting it in the refrigerator! He then put the mold on parchment paper and started applying the first set of fiberglass over the modeling clay with epoxy. Kerry would cut the fiberglass with something that looked to me like a pizza cutter, then lay it on the mold. From there, he would dab the epoxy in with the end of a paintbrush. “You see it disappearing?” Kerry said. “If you can’t see the glass, then it’s in good shape.” He kept dabbing. “This is what you’d have to do if we didn’t have Hal’s fairing. You’d have to put all this modeling clay on the airplane. And then you form this to where it fits and looks good. And then you glass over it on the airplane. We’re just experimenting; we don’t know if it’s going to work or not. If we can get a form, then we can make it fit and cut it to where it’s supposed to be. You use about three to four layers of glass to make the fairing. With this kind of weather, the epoxy dries fast. I forgot to put mold release on the modeling clay. So, this fiberglass is probably going to be stuck to the clay. We’re going to have to scrape it out.”

After a week or so of working on the mold and adding epoxy, scraping out modeling clay and making small adjustments as needed, he managed to finish it. He also was able to make some fairings for the gear legs using a similar process. Thank you, Kerry!

One Big To-Do List

Oftentimes, we would talk about things that needed to be done but then would forget because there’s so many that it’s hard to keep track! This is when my handy-dandy whiteboard came into play. I wrote down everything that we needed to do! This included installing the trim, ordering coils and a coax cable for the electronic ignition, getting a magneto from Kenny Faeth, running cables for the ADAHRS to the panel, installing another seat mount (more forward), making transition fairings, determining a location for the primer, sealing the firewall, shortening the ADS-B cable and connecting everything to the engine. We also needed to mount the alternator, oil cooler hoses, all control surfaces, wheel fairings, starter motor and all probes. And that’s just everything I could fit on one tiny whiteboard!

Miller Time

I love the warm days where the weather is great and everyone is out and about. Hangar 32 was a popular place one particular day, with eight cars parked outside the hangar! Everybody was having “Miller Time’’ while I worked on painting the baffling and the propeller flywheel. I can’t even remember what color it was, but it was ugly and the paint was peeling! We decided that black would look sleek. After taping off the sides, I primed and painted it. Kerry can’t stop working so he was chatting and working on the mold.

Cutting the Floorboards

Stan, Kyle, Tyler and I taped two large white poster board pieces together and started working on measuring a template for the floorboard. This would rest on multiple foam pieces fit between the ribs at the bottom of the floor. After making the paper template, we traced it with a sharpie on an aluminum sheet and started cutting it out with the fancy shears. Zach stopped by and helped me file the sides down so nobody would get cut on the sharp and freshly cut aluminum.

After finishing the floorboard up, it was time to change our focus to the control surfaces. We still needed to pick up the newly painted wings and control surfaces from Justin and his team and then attach them! I was looking forward to N2165U starting to look like an airplane again. It didn’t look like she would be making it to Oshkosh 2023, but at least we had made a lot of progress!

The post Second Chance Six appeared first on KITPLANES.

I have thought back to not only the past 10 years but also back approximately 18 years when I first decided to build the airplane and the choices that had to be made once the build commitment had been made.

The Data

In the first 10 years of its existence, the airplane has logged the following into its EFIS memory: 949.7 hours in Hobbs time, 830.5 by tach time and 773.0 hours in flight. It’s powered by a Barrett Precision Engines IO-540 built to Lycoming D4A5 specs—the spec Van’s recommends—and a Hartzell “blended airfoil” two-blade aluminum propeller.

Routine consumables over the last decade include the following: six Monster retread tires, four mains and two noses. Three sets of brake pads (standard Van’s/Cleveland). Four K&N air filters (I clean each one once and replace it every other year). I’ve replaced two ship’s batteries, the second replacement upgraded to an EarthX lithium battery. I also replaced two ACK ELT batteries due to expiration. I’ve recently replaced all firewall-forward fluid hoses. They were replaced at 10 years time in service recommendation rather than condition.

I’ve poured 182 bottles of Philips X/C 20W-50 oil, either consumed or replaced on schedule. I started out filling to the maximum of 12 quarts at the beginning and did the first couple of changes at 25 hours. Over time, I slowly transitioned to changing the oil at roughly 50 hours and replenishing to 7 quarts, only adding with 6 quarts shown on the dipstick. From experience, I have learned that anything above 6.5 on the dipstick will eventually be wiped off of the belly. Usually by me.

Failures, Replacements, Upgrades

I started with two first-generation Dynon Skyview screens, a Dynon com, a Dynon transponder, Dynon (single channel) ADS-B and Dynon autopilot servos for pitch and roll. They were mated to a PS Engineering audio panel and a Garmin GNS 430W through an ARINC 429 module. Over time, I’ve had one servo replaced under warranty due to failure and upgraded the pitch servo to linear throw for a nominal fee. I had one servo shear-pin failure, which was upgraded by Dynon to a more robust unit.

I added the Dynon yaw damper servo assembly and upgraded to the dual-channel ADS-B when each became available. I exchanged one of the EFIS screens due to a serial number recall and the com head unit due to failure (also covered under warranty). I also replaced the original Dynon sensor package with the upgraded Kavlico package due to a service bulletin.

Without a doubt, the biggest mechanical issue that I have experienced over the last decade was the in-flight failure of the MT prop governor (860-3), which resulted in an emergent diversion to an alternate field. About half a dozen of us users of the same model prop governor had catastrophic failures within a relatively short time. My failure occurred about one week after the previous one and a week before the service bulletin was issued. The results of this incident resulted in a removal and teardown of the engine for inspection by Barrett, which was covered by insurance.

It is important to note that this issue had nothing to do with Van’s, the RV-10 as a model, Lycoming or Barrett. It was an MT manufacturing issue coupled with unfortunate luck. Several but not all of the airplanes involved were RV-10s but to my knowledge no major damage or injuries were involved.

Firewall forward, I’ve replaced one Plane-Power alternator (warranty), one Sky-Tec starter and one Lycoming mechanical fuel pump, all due to failures or impending failures. Incentivized by failure, I added a B&C Specialty Products 30-amp standby alternator on the accessory case. I also replaced one of the original Bendix 1200-series magnetos with an E-MAG electronic ignition system.

About the Airframe

The Van’s airframe has been robust and trouble-free. I have complied with all of the (few) service bulletins the airframe has received, but have never found any incidence of cracks in those occasions where cracks were the reason for the SB. In fact, over the last decade, I have never had a failure of any part or component that is considered OEM by Van’s Aircraft. The only addition to the airframe that I have made that hasn’t already been highlighted was upgrading the wingtip landing lights to leading-edge LED lights by Flyleds.

Use and Enjoyment

Over the nearly 1000 hours logged on the airplane over the past decade, there are a few logbook stats that readers, especially those either still building or those considering a build, hopefully find interesting.

The airplane has landed at 72 different airports, from dirt strips to major international airports. Seven of the airports were in Mexico (before the unfortunate banishment of Experimentals). The Mexico flying was primarily in support of the Phoenix chapter of the Flying Samaritans organization, for which we flew 17 very rewarding trips.

We’ve flown five trips to AirVenture, staying each time at homebuilt camping. Out of those five trips, the only anomaly encountered was the previously mentioned loss of an alternator requiring an unplanned RON in Hays, Kansas, while Plane-Power overnighted us a replacement.

We’ve carried 151 separate individuals as passengers in the aircraft, of whom 26 were Young Eagles. We’ve also flown seven demo flights with potential builders. We’ve made three rescue/assistance flights (very rewarding), three guided group tours of the Grand Canyon/Lake Powell/Monument Valley region, two trips to Catalina Island and one trip each for a wedding, funeral and high school reunion.

We have also made two very rewarding flights to airplane camp on the centerline of the path of totality of solar eclipses. The first one was at Rexburg, Idaho, in 2017 and the second one at Sulphur Springs, Texas. Those are some of the most rewarding trips we’ve ever done.

The majority of the rest of our flight time has been commuting between our primary home base of Mesa Falcon Field (KFFZ) to our mountain airpark home at Mogollon Airpark (AZ82). The airplane cuts the two-and-a-half-hour drive to a convenient and scenic 30-minute flight.

The point that I want to stress with the trip summation is that the RV-10 is very much a capable traveling machine and not just a Sunday flier.

Decision Points

Before and during the build, I made countless decisions, some big and some small. I’m often asked if I would stand behind those decisions. For the most part, yes. Let’s break that down.

One of the major decisions is propulsion. When I was faced with that decision, believe it or not, there were actually more choices available than today. There was the “safe” choice of going with the Lycoming IO-540 engine that the airplane was designed around, either in new form from the factory or rebuilt form from one of the few choice shops. However, back in the day there was also a much-hyped Subaru option and a couple of automotive V-8 conversions vying for buyers with all kinds of blue-sky performance promises and (comparatively) low price points. I looked at all of them, and I count my lucky stars that I didn’t get lured into the hype. Without going into detail, I don’t think that any of the two or three dozen builders that (publicly) went automotive-based are still flying without eventually converting to Lycoming.

I have been very happy with my Barrett engine. If/when my engine time is up, before my personal stick time is up, I will likely either have Barrett build me another one or use my factory certificate for a new Lycoming. While many RV-10 builders are opting for composite three-blade props, I’m quite happy with my two-blade metal Hartzell.

Probably one of the most controversial things I did was build with air conditioning. In my case, I went with the Airflow Systems package and they have been great to work with. Installing A/C had its naysayers back then and it has them now. Living in Arizona, it has been a godsend for me and the enjoyment of my family and passengers. For an RV-10 or similar, I would do it again, no question. I also recommend the Aerosport Products overhead console with extra air vents, even if you don’t go with air conditioning.

I made my major build decisions during the transition from the old steam generation to the new glass panels. I came very close to buying a complete Blue Mountain EFIS. Boy, did I ever dodge a bullet there. I ended up with a first-generation Dynon SkyView that I have been very happy with. My system has features that even brand-new Boeings don’t enjoy. The system has been reliable and the integral autopilot is amazing considering the cost. Someday I will probably upgrade to newer versions, but I haven’t felt compelled to do so yet.

Closing Thoughts

The airplane has far exceeded my wildest expectations. All airplanes are a compromise of some sort or another, especially multi-mission platforms like the RV-10. Quite frankly, at the risk of sounding like the marketing wing of Van’s, I honestly cannot think of another airplane that combines the speed, durability, efficiency, comfort, payload and value of the RV-10. All in a package that is easy to maintain and to fly. The fact that my airplane enjoys a fair market value of roughly twice what I have invested in it is just icing on the cake. I also appreciate my fortunate timing. A decade ago engines were much less expensive and other factors—Van’s increased prices and laser-cut-parts fiasco among them—had not yet materialized. It was different building an RV-10 then than it is now.

Owning an RV-10 changes the dynamic around my next airplane build. Put simply, there’s nothing that does so many tasks as well as the RV-10, especially when travel is factored into the equation. Why build something near it when you have the Goldilocks airplane already? No, the next airplane will be for those short local hops during the last half-hour of daylight just for the sheer joy of flying. Additionally, as I age, it will also be for when I don’t want, need or qualify for a first-class medical or full-coverage insurance.

For those of you still building, all I can say is stay with it. Keep banging those rivets and stringing those wires and sanding fiberglass. Before you know it, you’ll be passing your 10th anniversary in the air. For me, it sure went fast.

Here’s to the next decade!

The post Ten For Ten: A Decade With an RV-10 appeared first on KITPLANES.

In the past, you needed a pack of AA batteries, or you jury-rigged some wires from a car battery sitting around, but today we have a better option! If you go to your favorite online shopping vendor, you’ll find hundreds (or thousands) of choices of standby battery chargers packs for cell phones – but they sell the same sort of thing in 12-volt flavors. For $30 (or so), you can have a little rechargeable 12 volt battery on hand anywhere you need it. I soldered alligator clips to on set of output leads so that I can clip them in place, and for another set, I have probes for a quick, precise  application of power.

It’s a handy tool to have in the shop, avoiding a bunch of random long wires that always seem to get in the way.

The post Twelve Volts Anywhere, Anytime appeared first on KITPLANES.

Some issues back I wrote a riveting three-part series about AN nuts, bolts and washers. The film rights were picked up by EAA and the series was turned into a webinar called The Nuts and Bolts of Nuts and Bolts. It skipped the theaters, never came out on DVD. However, on the heels of that brush with success my reader asked me to address rod end bearings. Mom, this one’s for you.

Rod end bearings are found terminating one or both ends of pushrods and, sometimes, control cables. Rod end bearings provide a self-aligning, friction-free interface between the moving parts of a control system as well as the means to adjust the functional length of a pushrod or control cable. That adjustability plays a key role in a rod end’s utility, as I shall describe with the following carefully chosen words about pushrods, but is also a potential point of failure. (Insert suspenseful music here.)

Carefully Chosen Words About Pushrods

Pushrods (and control cables) connect the moving parts of flight and engine control systems. They often bridge long distances and slash through airframes at unusual—sometimes varying—angles. Rod ends at one or both ends of a pushrod provide a low-friction interface between the moving parts and accommodate subtle changes in the geometry of the connection. They also reconcile the inevitable manufacturing and assembly variations that should be expected in this less-than-perfect world—their threaded interface affords adjustment to the functional length of an otherwise fixed-length pushrod. Without that adjustability it would be impossible for kit companies to manufacture pushrods that would serve each builder’s needs. We builders would be left to make or modify each pushrod to account for myriad variations we can’t help but build into our artisan airframes.

If weight didn’t matter, a fully threaded pushrod, trimmed to the correct length by each builder, would be the ideal form for each pushrod. But weight does matter, so most pushrods—those of any length, anyway—are made from steel or aluminum tubing. A well-designed tube-type pushrod will maximize the length of the tube and minimize the length of terminating threads. But here’s an important caveat: To provide the maximum range of adjustment for rod ends, thereby maximizing the range of the pushrod’s functional length, a pushrod’s threads must be long enough to accommodate a rod end’s full range of safe engagement. Threaded lengths shorter than that hobble the utility of a rod end. Threaded lengths longer than necessary can impact the pushrod’s strength.

Can I Get a Witness?

There are three things that require a builder’s attention when fitting rod end bearings: ensuring adequate thread engagement, capturing the pressed-in bearing in the event of a rod end failure and preventing the rod end from migrating on the pushrod. Here is how each is addressed.

Witness Hole. A witness hole provides a means for visually or physically confirming the rod end has minimally engaged the push rod. What is minimum thread engagement? While a definitive specification from an authoritative source is elusive, it is widely accepted that the witness hole must be located 1 to 1.5 times the diameter of its thread size from the end of the rod end. For example, a 1/4-28 rod end must have a witness hole no less than ¼ inch from the end of the rod end. Many pushrods are manufactured with a witness hole. When one is absent, you must drill your own. I prefer a 1/16-inch witness hole, but I’ve seen them as large as 3/32 inch.

Male rod ends lack the convenience of a witness hole but still require minimum thread engagement. If a witness hole can’t be drilled in the corresponding pushrod, marking the male threads in some manner, such as “painting” them with a marker or machinist’s dye, works well.

Proper rod end engagement is achieved when the witness hole is completely blocked. When thread engagement can’t be visually inspected, use a piece of 0.020-inch safety wire to probe the hole. If the wire passes through, minimum thread engagement has not been achieved. Never accept less than minimum thread engagement.

Capture Washer. Rod ends are typically a cast, forged or machined body with the bearing pressed in. That which can be pressed in can fall out if the rod end body cracks. If that happens the control linkage’s integrity is lost and dire consequences await. To prevent a full loss of rod end engagement, a large washer—typically an AN970 large area washer—is placed against any side of the rod end bearing that is not captured by other structure. The large washer keeps the bearing and rod end body in place in case they get separated. While the washer can’t prevent a failure, it can mitigate the consequences of a failure.

Check Nut. Rod ends are always paired with an AN316 check nut, sometimes called a lock nut or jam nut. The check nut prevents rod ends from rotating out of position. When installing female rod ends, the check nut is tightened against the rod end after the rod end has been adjusted. When installing male rod ends, the check nut is tightened against the pushrod after the rod end has been adjusted. A line of witness paint across the rod end and the jam nut, or jam nut and pushrod, adds a finishing touch.

Installing and Adjusting Rod Ends

Installing a rod end begins by making sure it has achieved minimum thread engagement. After that, deliberate adjustments can be made by turning the rod end farther onto the pushrod until the correct functional length has been achieved. If a pushrod has a rod end at each end, turn each rod end incrementally so they have equal thread engagement. After you’ve made the necessary adjustments, check once more that you have (at least) minimum thread engagement, lock the rod end in place with the check nut and paint both with witness paint.

If you run out of adjustment, do not accept that having less-than-minimal thread engagement is OK. It’s not. Something’s up and you need to find out what. Begin by checking that all the related parts are made and installed correctly. If you are dealing with kit parts, contact the kit manufacturer and lean on them for guidance in identifying and correcting the problem. It may be an incorrectly built or installed bellcrank or drive horn, an incorrect path between the two connecting points, an incorrectly manufactured part or a misunderstanding of what the plans are depicting. The problem needs to be identified and corrected. In my time supporting builders I encountered too many (and frankly, one is too many) builders who shrugged their shoulders, accepted what was before them and moved on without investigating why their assembly didn’t jibe with the factory documentation. That can have consequences that don’t become obvious until later, when the corrective action is much more involved.

As with most areas of homebuilding, one can dig as deep into a topic as one wishes or follow the accepted practices with little thought. I’m one who likes to know the “why?” of an accepted practice, as that gives me greater confidence, and flexibility, when executing a task. Installing rod ends is straightforward, but failing to recognize the potential points of failure can be catastrophic.

The post Best Practices Make Perfect appeared first on KITPLANES.

First of all, let’s come to a definition of wire. Of course, we all know what wire is…round metal (mostly round) thin threads meant to either constrain cattle or transmit electricity. I think it is the second one we need to deal with, barbed wire notwithstanding for the first one.

Now, some stuff you may never have considered before. What is the most conductive metal? Another way of saying that is, what metal provides the easiest path for electricity to go from one point to another? Ask that around the chapter barbeque and the most predominant answer will be gold. The predominant answer will be wrong. The correct answer is silver, followed by copper, gold, aluminum and then a whole bunch of stuff we don’t have to deal with.

Silver wire, for those of you who are building reasonable aircraft, is not available. After 65 years in this business, I’ve never seen silver wire.

So, copper wire is our metal of choice. Not quite so fast. Have you ever seen those beautiful roofs in the cathedrals of Europe? Mostly all green. The green is what we call verdigris and is a copper amalgam. They started out copper, but the years of exposure to a polluting atmosphere turned them into literally translated (ver [green] gris [made gray with vinegar]), but hardly what we want on our airplane wires. And verdigris forms on copper nearly instantly on exposure to polluted air.

There is a solution, perhaps not an optimum solution, but a practical one. Coat copper wire with a very-very-thin coat of tin (or tin’s son from the marriage of tin and lead: solder), and then you have an excellent conductor with a thin coat of “pretty good” conductor. The best of all possible worlds.

One more refinement and we are ready to go. Those of you familiar with house wiring know that Romex (solid copper house wire) doesn’t take a lot of flexing or vibration to work-harden and break. Since there is a fair amount of vibration in most of our aircraft, especially those of you “privileged” enough to fly behind a Jacobs radial (they don’t call them “Shakey Jakes” for fun), we had best figure out a way to keep solid wire from breaking.

The best way (so far as we can tell) is to use a lot of very small wires in parallel instead of one big solid wire. We call this “stranding” and it is designated on the wire spool like this: AWG #24 Strd7/32. Thus we have a #24 gauge wire made up of 7 strands of #32 wire wound in a spiral, and it is virtually impossible in the real world to flex this wire enough to break it. Yes, there is a mil-spec that dictates how many times a machine could bend this wire at a given bend angle to break it, but for our purposes (not being willing to sit there bending it back and forth a few thousand times to finally break it), it is not prone to flex breakage.

Somehow along the way, we needed to codify our wires so that the early engineers amongst us could specify what wire size we should use for a particular application. Since the electrical systems evolved prior to the United States’ entry into the world order, our predecessors picked systems for each country according to their measurement systems. It was a cacophony until somebody noticed that nearly every country eventually signed onto the United States system and thus was the universal adoption of the AWG (American Wire Gauge). England, of course not being too thrilled with those upstart colonies that beat them fair and square in 1783, adopted an identical system called the Browne & Sharpe Gauge (aka Birmingham Wire Gauge or Stubbs Iron Wire Gauge).

I think that the above copper wire table (downloadable as a true spreadsheet from www.rstengineering.com) might be a valuable addition to your collection of digital electronic tools.

More of Weir’s Weird Wires next month. Until then…Stay tuned.

The post Hi-Yo, Silver! Away! appeared first on KITPLANES.

I am hoping to catch some readers who are just now narrowing down their final choice for a first-time aircraft kit purchase. This is a big decision that will become a major focus of time and money for months to come. You have probably been doing lots of research to select the best kit that fits your needs. If you feel a little apprehensive, that is a good sign that you are taking this venture seriously! Having once been in this situation myself, let me shed some light on some critical issues that you might not have considered. I don’t want you to fall into an uncomfortable trap that might not be obvious at this stage of your building journey.

A common problem occurs when a kit builder finds they have encountered a construction task that is either confusing or appears too challenging to complete. Or worse, there is doubt as to whether the task was completed correctly and safely. The great news here is that popular kit manufacturers have nearly eliminated this issue over time with better documentation, tech support and building techniques geared toward first-time builders. We all have different talents and abilities when it comes to building. Most kit vendors have designed their products to ensure success for most first-time builders.

What Can Go Wrong?

It is easy to overlook that the kit manufacturer you have chosen does not make the engine you need to install. But because an engine is required for flying, they can steer you toward those engines that might be a good fit for your airframe—those having proper weight, power, etc. They might even sell you the engine for a one-stop shopping experience. You may get an economic advantage with this type of purchase, and at least you’ll know you are buying a recommended powerplant for your kit. Nevertheless, there are some things to be aware of.

That great documentation you used while building the airframe probably does not exist for engine installation tasks (also called firewall forward installation). Ask your kit manufacturer and find out if this is true. I cannot think of a more challenging effort than installing, plumbing, wiring and testing an aircraft engine. You need more and better documentation and tech support rather than less. Sadly, it rarely exists. This is a big bump in the road for many first-time builders.

What Tasks Are Involved?

Engine installation is one of the most complex and fascinating areas of the entire project. Once the large, metal block of an engine is physically mounted, you move on to attaching fuel lines, pumps, hoses, throttle cables, air ducts, ignition cables, batteries—the list goes on and on. If you are not familiar with the skills required for this step (and who is the very first time around?), then daunting is a good word to describe the entire task of engine installation.

Why does it have to be this way? The companies that make the airframe kits don’t usually know what engine you will install—and the engine manufacturers don’t know what airframe is being used. This arena becomes even more challenging when you consider that an engine mount is a custom item that needs to match a specific airframe to a specific engine. Who should design and create instructions for the first-time kit builder on how to install these?

If this is not your first airplane kit, then a lot of these issues are less challenging. But for the first-time builder it can easily be a showstopper when it comes to finishing the aircraft. Even if a company packages and sells all the parts needed for an engine installation, I’ll bet the step-by-step, easy-to-follow instructions on how to assemble it all won’t be included!

My advice to any first-time builder researching aircraft kits is to always find out what instructional help will be available when it comes time to install the engine. Even if the engine choice is not made at the time of airframe building, that issue does not go away.

What Are Your Options?

At the top of the list of kits that simplify engine installation is Van’s RV-12/RV-12iS. Step-by-step instructions detail every nut, bolt, wire and hose used in the airframe kit as well as firewall forward. This kit all but guarantees that the first-time builder will succeed! I am not aware of another kit model sold today that can match its all-encompassing documentation.

While this might look like the perfect first-time builder kit, remember that all things in life are a compromise. Examine this kit’s price tag, single engine choice and low-wing design. If these are not an issue, then you have a great option for a kit choice.

Next on the list of aircraft vendors that do a reasonable job of supporting firewall forward installation are those that strongly recommend a specific engine model. As an example, Sonex Aircraft has traditionally urged builders to use the engine they supply (the AeroVee) in their Sonex aircraft kit. If you go this route, you receive good instructions on how to not only assemble that engine (the engine is a kit!) but also very specific instructions for installation. Again, the drawback is that you are limited to using just this engine if you want this very high degree of firewall forward instructions.

The next and largest category of kit manufacturers is those that recommend a limited choice of engines that they will “support” in their airframe kit. What this usually means is that the kit manufacturer has assembled and sells a package of firewall forward components that are needed for a specific engine. With this package you have everything you need to complete your engine installation—and hopefully the package includes some documentation. Ask to preview this documentation before you buy. Is there enough detail for you to complete the installation? I can almost guarantee it will not be in the form of step-by-step details like the airframe instructions may have been. Hopefully, the kit manufacturer will provide support if you need it. By using their engine components, they should be able to help you if you get stuck.

Compare this to purchasing an engine model that has no prepackaged firewall forward components, even if the airframe kit vendor agrees it can work. You are then on your own to find the right parts. This is a common path toward failure for many first-time builders.

Another category of engine installation support comes from custom engine manufacturers that have tried to make it easy for you to install their powerplants. This effort includes firewall forward component packages, documentation the engine manufacturer produces and videos showing typical installations. In some cases, a great engine may not be that great if you struggle to get it installed correctly or don’t understand how to wire and plumb it.

Ask to preview the documentation so you will know in advance what you are getting into. Do not rely solely on promises from the vendor as to how easy it is to get it installed. Also do a bit of research, online and by talking to other builders, to be sure you will get the support you need.

Be nice to yourself by making it easy to succeed as a first-time builder. Choose your engine wisely. Plane and Simple!

The post Where Are the Instructions? appeared first on KITPLANES.

Anatomy of the Zenith Nose Gear Action

The Zenith nose gear column is free to rotate and move vertically within the top and bottom bearings. The bearings and bungee pin are fixed to the firewall. Normally, the bungee pin—and thus the firewall—are lifted by the bungee because the firewall top ends are fixed to the nose gear column. As a downward force is applied to the front of the airplane, the nose of the airplane will lower and the nose gear bungee will stretch. However, the nosewheel steering rods stay with the nose gear column as the airplane lowers. (See “DIY Firewall Boots,” KITPLANES, September 2009.)

Bungee Replacement

1. Start by making the bungee tool (Figure 1 and Photo 1).

2. Hang some weight on the tail tie-down to lift the nosewheel off the ground. Two cinder blocks worked for me on my CH 701 (Photo 2).

3. Then use a utility knife to slowly cut through the old bungee (Photo 3).

4. Next, remove the nose gear steering rods. Also remove the lower nose gear bearing pieces (Photo 4) and the nose gear top retainer (some Zeniths don’t have these). Then remove the nose gear and old bungee.

5. Push the new bungee about halfway up behind the bungee pin, which is behind the nose gear. Thread the nose gear column through the lower part of the bungee and through the top nose gear bearing while capturing the upper part of the bungee in the hook on the back side of the nose gear (Figure 2 and Photo 5).

6. Reinstall the bottom nose gear bearing pieces and the nose gear steering rods. Put the lower part of the bungee (now on the front side of the nose gear) on the tool you made (Photo 6). Position the tool over the protrusion on the front of the nose gear and lift on the tool (Figures 3 and 4).

7. With a little tug, the bungee will slide off the tool, which can then be removed (Photo 7).

The post Sagging Zenith Nose Gear? appeared first on KITPLANES.

That being said, I am still working my way through tons of self-inflicted modifications and custom-built components. It seems like almost all my recent work is going toward parts and pieces that are highly modified and will very rarely be seen. Completion of components like the exhaust system and the intercooler have taken some of the dreaded items off of the long to-do list. All these custom parts are time-consuming and give little visual progress when looking at the whole picture.

Some of this extra time consumption is also commonly experienced by the perfectionists or believers of “the devil is in the details.” Meticulous builders spend hundreds of hours deburring, rounding corners, smoothing edges and making things fit “perfectly” before final assembly. Motivation can lag when you spend so much time doing things that may not help the plane fly any better—and may not even make it look better, at least not to the usual onlooker. It is even worse when you spend all the hours/days on these things and there is literally nothing extra that is assembled on the airplane.

For instance, you can easily spend weeks/months building the wings or fuselage and not feel like or see that you have really made any progress toward the final project. But once the completed wings are sitting next to the completed fuselage and you spend one single day mounting the wings, the visual progress is taken to a whole new level! When this happens, usually motivation experiences an amazing boost as well.

Morale Arrives in a Brown Truck

I am in the stage of spending huge amounts of time without seeing much visual progress, but I am still chugging along with the build. The last morale boost from visual progress came with meeting the UPS truck for the delivery of my Beringer wheels and brakes. It is always exciting to get a big box of airplane parts. The tires, wheels and brakes have been on my mind ever since I decided to build the Zenith 750SDX. While I like the look of the factory demo on the 27.5-inch main tires and the standard wheels, I knew that I wanted mine to be different. The Beringer wheels and brakes have caught my eye maybe because they are different and aesthetically pleasing or maybe because I have heard so many good things about their performance. Or it could even be the Beringer Red they use as their standard color. Some of you have probably already guessed that red is my favorite color. Wait, I shouldn’t be so discriminating on colors, so let me rephrase that: I like any color, as long as it’s red.

Anyway, even though the Beringer system isn’t mounted yet, it is motivating to hold the red Beringer wheels up to the tires and have them next to the airplane so I can visualize what it will look like once it is up on its own feet. It did take a while to nail down exactly what I wanted for this plane. The stock setup for the main gear on the Zenith CH 750 SD uses Matco 8-inch wheels along with 27.5-inch Desser/Aero Classic tundra tires. I was OK with the tire size because I mostly land on moderately rough farm fields, grass strips and sandbars—I very rarely land anywhere near the larger rocks/boulders where 31- to 35-inch tires are needed or required. However, after talking with Beringer for quite some time, I finally decided to go with the larger 10-inch wheel/brake setup. It is way overkill for the braking and load capability needed for the 750SDX, but this is one area that I would like to “install it and forget it” as much as possible.

Once we got all the technicalities finalized, I am left with figuring out the tires. I didn’t mind sticking with the 27.5-inch tires, but they are for an 8-inch wheel. The next closest size and lightest weight tire I have found for my 10-inch wheel is the Desser 29-inch tire. Desser also has 31-inch tires, but I really do not need or want the extra size, weight and increased drag by going all the way to a 31-inch tire. You might ask why I am sticking with the Desser tires instead of another brand. It is my understanding that Desser takes new Aero Classic ribbed aircraft tires, grinds off the ribs, then buffs the tire to a smooth finish for the “tundra tires” that I will be using. They still have plenty of rubber and hold up very well to all kinds of wear and tear, both on and off asphalt.

Plus, I had good luck with the 22-inch smooth Desser tires on my Super701. I feel like they were a huge improvement over the stock tires when the aircraft is being used for off-pavement operations. I think they are the best compromise for handling moderately rough off-airport sites without sacrificing lots of extra weight and drag and I would recommend that setup for anyone with a Zenith 701. I installed the 22-inch tires without tubes and with a small amount of silicone adhesive applied to the tire bead when installed. This has worked great for me, even when I have aired the tires all the way down to 3.5 psi for several abusive ops, and I have never had any sign of the wheel slipping inside the tire or any trouble with the bead coming loose from the wheel. It is like landing on pillows after I installed the 22-inch tires.

In case of a flat, these tires can usually easily be plugged in the field without special tools for removing the tire/wheel or without having to disassemble and mess with a heavy tube. Since these have worked so well for me, I plan to do the exact setup with the larger tires and wheels on the 750SDX. The next step is to figure out how to mount this setup to the Zenith aluminum main gear legs. I will go into this in better detail next time, as there are still a few uncertainties to work out with the install.

Nosy Business

As for the front/nose tire setup, well yes, I am modifying that also. Keep in mind that not all tires of the same labeled size are actually the same physical size. For instance, the standard Carlisle 8.00-6 tire that is included in the Zenith 701 kits is quite a bit smaller than the Aero Classic 8.00-6, and the Zenith 701 requires a new fork or a fork extension modification to work with the Aero Classic tire. The Zenith CH 750 SD comes with an Air Hawk 8.00-6 tire that very barely fits inside the nosewheel fork. I have opted to increase this to the larger Aero Classic 21×8.00-6 tire that is ½ inch wider and around 1.5 inches taller than the Air Hawk. I think the nose tire is the limiting factor for using these Zenith airplanes when “off-roading,” so it doesn’t make sense to increase the main tire size without adding a little extra rubber and floatation capability to the nose tire as well. Hence, another major modification. I have also mentioned previously that a new nose gear strut assembly with full shock capability is in the works. The second prototype is getting ready for release and I hope to have it installed soon. I have a new nose fork getting ready to be produced by a local machine shop that should work really well to couple the larger Aero Classic 21×8.00-6 tire to the new front suspension strut. I am hoping all of this will make the perfect sweet spot for the 750SDX and what I desire to be able to do with it. I’ll share a lot more info about all the landing gear setup in the upcoming articles.

Panel Mods

As with everything else that is modified on this bird, the instrument panel is going to be one of a kind and take a tremendous amount of time to complete as well. A fair amount of this time has already been spent sitting in the cockpit or in my chair beside the airplane brainstorming ways to make it work the way I want. Several people have mentioned how clean the “switchless” and breakerless panel is in my Super701. All the necessary switches are hidden behind a small access door and I use the Vertical Power electronic breaker system.

While I have thoroughly enjoyed this setup in the Super701, I intend to make the 750SDX panel cleaner and smaller to allow even better visibility. The Vertical Power setup has worked flawlessly and I like how it integrates all the electrical system information and functionality into the EFIS. You can see everything that is turned on or off and the amount of power each circuit is consuming, set alerts, turn circuits on/off and even reset them if needed, directly from the EFIS. I will go into the Vertical Power system more as I get closer to the wiring phase of the build.

I’m matching the Vertical Power system to a Garmin EFIS, in part because it’s the only system I have found that will allow me to control the entire electrical system through a single EFIS touch display. My main panel will have no switches, lights, extra gauges, breakers or anything else to clutter up that space in the cockpit. The switched circuits will be controlled either through the Vertical Power system that is coupled to the Garmin screen, startup/backup switches underneath the main panel or the switches that will be located on the hand grips.

The Garmin radio and transponder will also be controlled through the Garmin EFIS screen. There are a lot of logistics involved with figuring out how and where to install and make all of this work, but I am confident it can be done nicely and reliably. To begin implementing the framework, I will be starting out with some of the Zenith components used with the Unpanel setup in the factory demo CH 750 SD. I will not be using the large articulating arm because it is fairly heavy and I do not desire the extra positioning offered by it. I will basically be building a center pod-style panel that is stationary. My EFIS may not be in the perfect line of sight for the best “take a quick glance” and I should probably go ahead and point out that this will only be a VFR rated airplane. I firmly believe that while flying a STOL (short takeoff and landing) airplane, the pilot should develop a good feel for the plane and spend almost all the flying time looking outside the cockpit.

When building these kit airplanes, you just have to be persistent enough to continue putting pieces together until you run out of pieces and try not to let things that may seem difficult get you into a slump. If done correctly, someday it will be a flying aircraft and the reward will be epic! That’s what we have to keep telling ourselves. So stay motivated and build on! Until next time…

The post Building the 750SD XTREME: Part 12 appeared first on KITPLANES.

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Rod ends are commonly used in Experimental aircraft for hinges, the most common example being in the empennage of RV-series aircraft. From a strict structural engineering perspective, this is an “off-label” use, since the rods see bending loads perpendicular to the thread axis (nominal loads are tension/compression along the axis, and that is how they are rated). However, in our applications the loads are typically small enough to be safely handled by the rod end (though for history buffs I’ll point out that the 1991 crash of the race plane Tsunami was in part attributed to a failure of a rod end loaded in bending). For example, manufacturer Aurora limits the bending loads to just 10% of the nominal load stated in the catalog.

One of the advantages of using rod ends for hinges is that it makes aligning the rotational axis easier since you can adjust the length (x-axis) of individual rod ends in order to achieve collinearity for the whole control surface. (It’s up to you get the z-axis correct!)

Since rod ends typically screw into a horizontal or vertical spar, the back side of which is often inaccessible, it is customary to use nut plates to secure the rod end. As Vic Syracuse has pointed out numerous times in his own articles, it is essential that a jam nut be incorporated in the rod end assembly as this not only helps prevent the rod end from loosening, but more importantly ensures that the rod end is primarily stressed in bending only from the point of the jam nut forward (minimizing stress on the rod end) and doesn’t transfer those bending loads to the nut plate.

Installation Tool

Screwing the rod end into the nut plate can be challenging. The trick is to grasp the body of the rod end without putting loads on the ball/race as the rod end is screwed in. There are several good DIY ideas on Doug Reeves’ VansAirForce.net (example). For my RV-4, I fabricated a tool from ABS and it worked fine. I liked that the tool won’t damage or mar the rod end. Avery also makes a tool similar to the one I describe that is available from Aircraft Tool Supply Company.

My SR-1 race plane uses rod end hinges for the empennage. Unfortunately, my ABS tool was too bulky to fit in the drag spar cove. I therefore constructed the low-profile tool shown at the beginning of this article. Material is simply a 4-inch length of ½-inch electrical metallic tubing (EMT) from the hardware store. I inserted a piece of 5/8-inch wooden dowel in the tubing and clamped it into the vise of my Bridgeport and milled a slot in the end with a 3/8-inch end mill. At the other end I drilled a 3/16-inch hole followed by a #12 reamer. A piano-wire hinge fitting pin (described below) is inserted into the hole and allows you to torque the rod end in.

Since the tool itself is a smaller diameter than the rod end, the cutout required for access is set by the diameter of the rod end body, not the tool. For folks who don’t care about a low-profile tool, slightly thicker wall aluminum tubing would be easier to machine. And since aluminum is softer than the steel rod end body, you’ll be less likely to mar the rod end as you torque it in.

The fancy version of this tool incorporates a 1/4-inch socket instead of the cross pin. I simply used a 10mm impact socket and epoxied it into the end of the tool. Works great!

Alignment Tools

When aligning control surfaces, you’ll be fitting the surface multiple times in order to get everything lined up. Rather than use AN3 bolts for this, when building the RV-4, I made a set of fitting pins from 3/16-inch piano wire that are much faster and easier to install and remove. The pins are in the dogleg shape as shown in the photo. Similar to the Avery tool, an unused pin can be slid through a hole in the opposite end of the tool to act as a T-handle if you forego the socket-drive approach described above. This is not a new idea and you can see a variety of ideas for fitting pins online at forums like VansAirForce.net.

As noted earlier, one of the advantages of using rod ends as hinges is the ability to make sure the rotational axes of the rod ends are collinear. The next tool helps to establish this axis. It is comprised of a pair of drilled AN3 bolts (or whatever size bolt the rod end takes) that are also center drilled with a 1/16-inch or #40 bit.

For the end drilling operation, first file or belt sand the end of the bolt flat; otherwise the bit will wander. Clamp the bolt in your drill press and spot drill the end with a bit approximately the same diameter as the bolt, just enough to get the surface concave. This will prevent the smaller 1/16-inch bit from wandering. Go slow, using new bits and a small amount of WD-40 as cutting fluid to avoid breaking the bit.

Step by Step

Follow these instructions and you should be able to establish a straight line through your rod ends.

1. Insert the first center-drilled bolt through the far left rod end and thread on a jam nut. Thread steel wire through the center of the bolt and out through the side hole, then (un)screw the jam nut until it holds the steel wire tight.

2. Run steel wire through the center of the rod ends and bearings.

3. Prep the far right rod end with the other center-drilled bolt and jam nut.

4. Pass steel wire through the bolt, pull as tight as possible by hand and tighten the jam nut to hold the wire in place.

5. To achieve maximum tension on the wire, spacer washers can be fabricated by slotting 0.062-inch-thick aluminum AN3 washers and inserting them between the head of the bolt and the ball of the rod end.

6. It’s difficult to tell from the oblique perspective, but the right ball end still needs to come out a half turn in order to center the wire in the middle bearing.

7. Once the wire is perfectly centered, the rod ends are marked with a small dot of red (left/port) or green (right/starboard) nail polish to indicate the orientation (up or down) of the rod end in case it needs to come out. Again, once final assembly is finished, the jam nuts should be tightened and marked with nut lacquer or torque striping to indicate they have been final torqued. I also use red and green nail polish to differentiate between left and right parts that are otherwise identical looking.

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