Tabla de contenidos para January/February 2024 en KITPLANES

In the last quarter of 2023, pretty much all the homebuilt-aircraft world could talk about was trouble at Van’s Aircraft. The unquestionable leader in kit sales and number of aircraft flying, Van’s confessed to cash flow problems in October and then, in early December, filed for Chapter 11 bankruptcy protection. As Christmas neared, builders who had placed deposits on kits were informed of increased kit costs and provided an option: agree to the increase, on average about 32%, or decline and have their purchase agreements canceled, their deposits likely to be repaid but only over a period of time. As much as five years. It was an awful place to put your customers. And yet within 24 hours of Van’s notifying the first 500 (out of about 1500) customers with…

It’s a common misconception that the only engine for Van’s RVs is a Lycoming—or a Lycoming clone. It’s true that’s the most common choice but not the only one. Van’s has, in fact, considered other engines—it flew the RV-10 behind a 210-hp Continental sixcylinder IO-360 but never offered the firewall-forward kit because builders indicated they wanted the most horsepower available. And then almost two decades ago, Van’s embraced the Rotax 912 for its then-new RV-12. In the intervening years, many LSA RVs have soldiered on with the dependable little powerplant—originally the carbureted 912 ULS and more recently the injected, computer-controlled 912 iS. The engines have proven perfect for the job and many have wondered if that same technology couldn’t be used on larger (and faster) RVs. The problem was power.…

Just as airplanes are legally grouped as certified or Experimental, engines follow the same scheme. Certified engines are specific, FAA-certified models sold on certified airplanes such as Cessnas and Pipers. These come only from certified engine makers such as Continental, Lycoming and Rotax and are rigidly specified right down to the exact part number rod bolts and so on. On the other hand, Experimental engines can be just about anything and sometimes are. In practice many Experimental engines closely follow certified practice with certified parts, but wild creativity is allowed. Using a new certified engine on an Experimental airplane is certainly no problem other than it’s the most eye-wateringly expensive option available. Also, a certified engine must be kept absolutely stock to retain its certified status. If you modify it…

Building Experimental aviation engines is a tough business at best, so engine programs come and go. Furthermore, as sport aviation blossoms into the competition arena (pylon racing, hard-core aerobatics, STOL competitions), the general kitbuilding populace is being exposed to high-strung engines not really suitable for mainstream aviating. Therefore, below is a gathering of currently limited application or not-for-sale engines and parts of interest. Some are new projects coming together, others are old programs gliding along, some are hot rods. Just because they’re listed here doesn’t mean they are somehow second-rate or might never see production, but at least at our deadline they either weren’t for sale or in custom-build status or highly specialized for mainstream kitbuilding. Altruair Based in San Diego, engineering firm Alturair is difficult to categorize if only…

There’s a menu item in the uAvionix AV-30 small-scale EFIS that shows total time. I landed on that while updating software recently and was surprised to see I’d spent more than 300 hours using the instrument in my GlaStar. Since the airplane’s panel is about to go under the knife—should I say wire cutters and DB-pin crimper?—and the AV-30 will be returned, it’s a good time to consider where it started and where it is today. I installed the AV-30 in 2020 to join a pair of Garmin G5s. My immediate impressions were good. The basic functions of the AV-30 were mostly right on—its attitude solution was always very solid and its pitot-static performance was dependably good. The display is plenty bright. In 300-plus hours, the AV-30 has been 100%…

On March 16, 1966, millions watched as success turned to tragedy on national television. Here is a partial transcript of that moment: Skipper: “Gilligan! You can’t fly. It’s impossible!” Gilligan: “I can’t?” Skipper: “No!” With that, Gilligan stopped hovering above a hut and crashed to the ground, his homebuilt wings and dreams broken around him. Skipper: “Gilligan little buddy, are you all right?” Gilligan: “Why’d you have to say that? Impossible? Why’d you have to say that?” Like Gilligan, I built an airplane that couldn’t be flown—or shouldn’t be flown, I’m not sure which. Not everyone is clear on their stance. Like Gilligan, I built my airplane in blissful confidence. Like Gilligan, I flew my airplane successfully before being told I couldn’t. Unlike Gilligan, I continued to fly my airplane.…

Last summer I had the chance to get some hands-on experience with TIG brazing. Other than a YouTube video or two, I knew next to nothing about it. My tutor, Mr. David from Lemoore, California, covered everything from the TIG machine settings, his favorite torch and why he’s using TIG brazing instead of TIG welding for an ever-increasing number of projects. The first thing to know is brazing and welding are two different things. Welding, as opposed to brazing, is the joining of metals by fusing two or more parts into one. Most aircraft welding is done with either tungsten inert gas (TIG*) or an oxyacetylene gas rig. In either case you heat up the base metals to create a small molten puddle, then rhythmically daub filler rod into the…

Way back in March ’23 (deep in snow here), I gave you the problem of Ernie, who needed a flashing light to see when something is being said on the radio. Finally, we’re going to finish the project by making a PC board for brother Ernie. I was hoping to get it done in time for him to make his trek to Oshkosh, but the PC board gods (demons?) declared otherwise. Between March and September, I started the “PC Board Series” and called upon Ernie to demonstrate the full usefulness of a homemade PC board. I freely admit that as a college teacher, I would have given a student a C (out of pure generosity) if (s)he had turned in a board like this. Generally, the C would have followed…

For ages one of the most common laments in aviation is we’re still flying around behind ancient engines. LyConsaurs they’re called, and when in the world are we going to move on to something designed after the demise of vacuum tube computing? Maybe, I’m beginning to think, we already have. No, I haven’t been smoking a strangely long pipe or just returned from a selfrealization retreat, but I have been doing something eerily similar: writing the Engine Buyer’s Guide found elsewhere in this version of the KITPLANES® thicket. At times compiling such a story does approach a hallucinatory exercise, what with all the numbers glazing over. But in those moments of clarity it became obvious there are many more than just the familiar horizontally opposed powerplants in play. Even after…

You’re hearing a lot more about angle of attack (AoA) flying these days and that is no accident (pardon the pun). From AOPA to EAA—not to mention a number of prominent flight schools and universities—flying by angle of attack is getting promoted as a way to stay away from accidental stalls in demanding flight maneuvers. Angle of attack indicators are becoming more common—especially in the Experimental aircraft world—because most EFIS manufacturers have the technology incorporated in their hardware and software, making it simple for all pilots to have the capability by just adding the appropriate pitot tube (which they might even already have) and doing some calibration work. We know this is probably a change to the way many pilots have learned to fly—or have been flying for their entire…

If you compare the dry weight of a Rotax to the dry weight of a Lycoming, you quickly see one reason why the product of Austrian design is so attractive to aircraft designers—the Rotax is much lighter! Rotax says the 915’s dry weight is 181 pounds (including electronics and turbocharger) while your average Lycoming O-320 weighs around 250 pounds. That’s why, of course, you need to have an extended nose—the lack of weight up front needs to be taken into account when doing the weight and balance for the design. So how does the Rotax-powered RV-9A do? We took a peek at Lockwood’s W&B sheet to find out. Van’s lists the empty weight of a Lycoming-powered airplane as 1028–1075 pounds. Since Van’s factory airplanes are known to be built very…

Sporty’s has enjoyed sizable success with its PJ-series portable transceiver. It’s priced right, backed by good support and has smart features. The latest in the lineup is the L6, which has all of the same basic features of the current PJ2+, but with a direct plug-in LEMO headset interface in place of the twin-plug GA headset interface. For users that only fly with LEMOequipped headsets, the L6 makes sense for convenient on-the-fly backup. Unplug the headset from the panel and plug directly into the radio without any adapters. Seamless Backup If you’re building a modern panel, you’ve likely thought about panel accessories like power ports—including a singleplug LEMO headset interface for at least the pilot and copilot audio jacks. The LEMO interface is convenient because it not only reduces the…

I’ve lived homebuilding’s full spectrum, from dreamer to attempted builder to awardwinning builder working for an upstart kit-airplane company that grew into a solid player in the industry. I was in the industry for more than 20 years, supporting builders on a daily basis. I spent much of my day combating inaccurate information someone was given on the internet. I write often on the impact people can have on someone’s success, even on their ability to get started. The reason? I’ve seen the impact the Skippers of the world can have and I’d like to give them all a swift swat with a sailor cap. The fear and doubt they spread is far greater than the challenges you’ll experience drilling a hole, sanding fiberglass, installing a bolt or fitting a…

One process I’ve only dabbled in (way back in high school) is gas welding, which requires an oxy-acetylene rig. A gas rig includes oxygen and acetylene bottles, gas regulators, hoses and a variety of tips for welding, brazing and cutting. If you can master flame welding, you can pretty much weld anything, not to mention brazing, silver soldering, cutting and heating. There’s a scene in the 1957 film The Spirit of St. Louis where Charles Lindbergh (played by Jimmy Stewart) first meets Frank Mahoney at Ryan Airlines in San Diego. Lindbergh wanders into the shop and encounters Mahoney, with welding goggles on, frying up a batch of Pacific sand dabs for lunch using a gas torch with a rosebud heating tip. Try that with a TIG welder!…

A decade ago, we highlighted the almost bewildering array of WW-I replicas made by Airdrome Aeroplanes by putting test pilot Harvey Cleveland and the Sopwith Baby on the February 2014 cover. Inside, Scott M. Spangler reported that designer Robert Baslee was fascinated by WW-I aircraft, quoting him as saying, “I’d always wanted a Fokker Dr. 1 Triplane.” In the feature, Spangler wrote that Baslee noted “there were a few homebuilt replicas available…but he wasn’t eager to invest 10,000 hours in building one of them. So he sat down with the Triplane’s three-view drawings and applied his experience as an engineer, machinist and handson homebuilder to find a better, quicker way. Before starting construction, he called a friend who’d graduated from Cal Poly, ’the same school Burt Rutan went to, and…

Despite the fact that all pilots are taught about the speed at which a wing stalls—it doesn’t! A wing stalls at a specific angle of attack. Lift is a mathematical product of speed, lift coefficient and some magical constants. We talk of a “stall speed” because for a given amount of lift (which equals weight times load factor), there will be a speed at which the wing is at an angle of attack that stalls. The stall angle of attack is a constant number for a specific airfoil. Vary the “weight” (actual weight times load factor) and the speed varies. The angle of attack at which the wing stalls is always the same, so an indicator that shows you AoA will always show where you are in relation to the…

Over time, two-stroke engines in aviation have been supplanted by four-stroke units, trading low weight for a perception of greater reliability. (Fact is, two-strokes are less tolerant of abuse and mismanagement than their Otto-cycle brethren.) Today the two-stroke aircraft engine survives in aviation’s most weight-sensitive nooks such as trikes, powered parachutes and basic ultralights. It’s also a contender when purchase price is paramount, as with expendable drones. Thankfully some of the best two-strokes continue. The quality Hirth line out of Germany is available from Phil Yager at Northwest UAV in Oregon. Servicing existing Hirth engines with parts, overhauls, used engines and Blue Max oil is longtime Hirth specialist Matt Dandar in Ohio. Hirth has been in the airplane engine business for 100 years and its impressively numerous engine models range…

While sorting through the parts and pieces of your new aircraft kit, you may discover that a number of those parts are made of bare steel. They stand out because they’re noticeably heavier than aluminum components and their surface appearance is unique. At some point you’ll realize that these parts are going to require some protection from rusting. Do we paint these or are there other alternatives? Most (but not all) aircraft kit manufacturers that I have dealt with deliver their steel parts “bare” so that the builder is left with the decision and effort to protect them from the elements. While aluminum components can be left unpainted (and polished if desired), steel should never be left without some kind of coating to maintain its integrity. Steel will rust in…

I will never forget the day. August 13, 2016. My wife and I were returning to Arizona from a nice trip to Utah and our timing was looking to be perfect for a gorgeous sunset view of the Grand Canyon as we passed along the eastern corridor of the SFAR. Our RV-10 had a little over two years in service and just under 300 hours in the logbook and had been performing wonderfully. Little did I know that we had a ticking time bomb on board. We had just leveled off at 11,500 feet for the airspace clearance when my cursed (say it as two syllables) prop governor decided to disembowel itself. Our first indication of a problem was a sudden deceleration of the airplane. The oil indications, both pressure…

To stay at a constant safe operating temperature, the engine of an airplane must reject excess heat to the surrounding air. To properly cool the engine, air must flow into the engine compartment from outside the airplane, absorb waste heat from the engine and then flow overboard to carry the heat away. In previous editions of “Wind Tunnel” we have followed the cooling air through the inlets, into the upper plenum, over the cooling fins on the engine’s cylinders and into the lower plenum. Once the air enters the lower plenum it must leave the airplane and return to the outer airflow, carrying the heat it absorbed from the engine with it. We now turn our attention to the lower plenum and the outlets through which the cooling air leaves…