CubCrafters EX-2 363i

Product development has many mothers. Sometimes you create a new airplane for a particular set of missions. Sometimes you take that design and tweak it based on customer feedback, advances in manufacturing capability or simply to crank up your market share and get your brand some juicy press coverage. And sometimes necessity is the driver.

The curious case of the CubCrafters EX-2 CC363i project derives from the latter influences. Originally built with a carbureted O-340 and a fixed-pitch prop, the EX-2 has long been the “step up” aircraft from the LSA-compliant SS. It slots in below the EX/FX-3 in weight and power. Think of the EX-2 as the Honda Accord with the four-cylinder and the EX-3 as much the same car with the sweet-sounding V-6.

Back to the EX-2, then. All was going well with the EX-2, sales-wise. Same for its FX-2 sibling, which makes this a good time to unravel the EX and FX nomenclature. Simply put, both are Experimental/Amateur-Built aircraft. The EX was designed to be shipped out and built at home, whether that home is your garage or airport hangar. The FX is the very same airplane but it goes through CubCrafters’ unique builder-assist program. A bit of further background here: Eligibility for the FAA National Kit Evaluation Team (NKET) program includes proof that the kit itself does not intrude on the builder doing the “major portion” of the work. The NKET checklist is broken down by tasks, where builders are given credit for both assembly and fabrication, and that credit is broken down to, say, fabricating a wing rib. It doesn’t say the builder has to fabricate all of them, so doing one gets the builder credit for all.

For CubCrafters’ builder-assist program, the usual preference of having the assisted builder do much of the assembly work is turned on its head. Instead, the builder comes to the Yakima, Washington, factory and participates in several aspects of the fabrication, including working with fabric, carbon-fiber composites, metal and control systems. Once the builder has completed the requisite tasks, the parts are collected and joined with parts built by the factory. These parts are, later, largely assembled by company technicians, with the builder returning at a later date to help with the final touches and to get some assembly credit. In the end, all the boxes earmarked for the builder have been checked off and there stands a beautiful new airplane. In addition, the builder can elect to do the Phase I flight test or can, for a fee, have the factory do it; most FX-series builders let the local pros do the job.

Back, once more, to the EX-2. Soon after COVID arrived, we all know that our supply chains got crimped like an elephant stepping on a garden hose. All manufacturers struggled, but Continental especially. And it’s Continental that makes the key components for the O-340 for the SS and EX-2. Builders who had already started their EX-2 had been waiting (somewhat) patiently for Continental to resume production of the 340, while CubCrafters itself had to delay starting any new FX-2 builds until it knew engines would be available. For builders who didn’t want to move up to the EX-3 or FX-3 programs with the Lycoming-sourced engine, the only solution was to continue waiting.

At about this point, CubCrafters began devising ways around the bottleneck, and the result is the airplane you see here: the EX-2 CC363i. Bear with me for a bit more unraveling of the product line. In general terms, the EX-2 and EX-3 are similar airplanes, only the -3s got the 360-cube engine, fuel injection and a constant-speed prop by default. It’s true that the EX-3 (and FX-3) were developed for the larger engine, so they’re a bit heavier—the listed typical empty weight is 982 for the EX-2 and 1023 pounds for the EX-3—but the EX-3 also has a 2000-pound maximum gross weight, 135 pounds more than the EX-2. The EX-2 also has a lower Vne—141 versus 170 mph—and other performance differences that come from the power differential. Remember that the CC340 was rated for 180 hp while the 363 is rated at 186 hp. The EX-3 arrived as an upgrade from the EX-2 but the price differential is what kept the EX-2 viable and popular.

Bottom line is that the CC363i/EX-3 airframe was a known quantity, so the challenge was to fit the 363 to the lighter airplane and not give up too much useful load. Already the Carbon Cubs have extensive weight-saving measures ahead of the firewall, including a carbon-fiber cold-air induction system, lighter sheetmetal oil sump, aluminum (instead of steel) intake tubes, lightweight starter ring gear and a magnesium accessory case cover. What’s more, because the 363 runs a Light Speed electronic ignition triggered off that ring gear, the accessory case no longer has the mag-drive gears, saving weight there as well. From a manufacturing standpoint, CubCrafters sends its exclusive accessories to Lycoming, which builds the engine and commits the test-cell runs with that equipment in place. The engine then comes back to CubCrafters, where it’s fitted with additional lightweight accessories.

It’s fair to say that since CubCrafters has been building these things, no part of the airframe or any of its systems has escaped the relentless questions of, “Can we make it lighter? Or stronger?”

CubCrafters took the opportunity to rework the cowling for improved cooling with the 363 but also fitted carbon-fiber conventional baffling, replacing the plenum system used with the 340. The decision to go with fuel injection on the EX-2 363 was partly for weight and partly for packaging. Ditching the carb also meant repurposing one of the exhaust heat muffs for the cabin, so the latest version has a lot more cabin heat to play with, no small item in an airplane intended for all-season flying.

Of course, the EX-2 CC363i was designed for fixed-pitch props (with a non-counterweighted crank) and does not accommodate constant-speed options. The company is running the 82-inch Sensenich 2G0M8-C82BG prop that can be trimmed to 78 inches and has a wide range of pitch adjustments via a clever pitch-pin arrangement. (Changing pitch can be a 15-minute job with experience.) CubCrafters will also offer all of the Catto fixed-pitch props and typically recommends a 78×54 (diameter and pitch) for cruise, an 80×50 midrange all-purpose prop or an 84×43 STOL-biased prop.

The amount of detail refinement on the EX-2 CC363i partly explains why it’s not been the work of a moment for CubCrafters. That and the fact that the factory is running at full capacity and has been for a couple of years now. Want a new Cub? Sure, but your production slot will probably be in 2024, and maybe not even early in the year.

Where do we end up on the EX-2 conversion, then? Amazingly, the 363 package in total is just 7 pounds heavier than CC340. And it’s not like the 340 is a tubby engine; with tapered barrels, it’s competitively light for the horsepower. It’s just that CubCrafters has scrutinized every piece of hardware ahead of the pilot’s heels to achieve this.

The CubCrafters airframes have not been static. Both the EX-2 and FX-2 (along with the EX-3 and FX-3) are considered second-generation Carbon Cubs, primarily for their use of the G-series flight controls on the wing. During development of the XCub, it became obvious that Cub-style aerodynamics weren’t going to work at the higher speeds available for the ever-more-powerful engines. That brought the G-series devices, which include lowered pivot points for both flaps and ailerons, as well as modifications to the cove in the wing trailing edge.

The goal was to create a larger gap between the wing and the flaps when deployed, for better lift; the more air you can move over the top surface of the flaps, the more effective they are. For the ailerons, high roll forces at comparatively high indicated airspeeds spoke to a need for change there, too. The lowered hinge point, by 1.5 inches compared to the first-gen Carbon Cubs, along with a recontoured upper aileron surface, places a force-countering leading-edge nose that helps lighten roll forces at higher speeds.

It’s likely you can recite the rest of the EX-2’s specs from heart. A steel-tube cage, artfully supplemented with carbon fiber in key nonstructural places. The flat-bottom wing spans a bit more than 34 feet for a total wing area of just under 175 square feet, a more than decent amount of wing for an 1865-pound airplane. Conventional fabric-covered tail feathers have both mass and aerodynamic balancing—horns ahead of the hinge line—and both the elevator and rudder have optional gap seals to improve effectiveness at low speeds. Like the Cubs of yore, the EX-2 has a trimming horizontal stabilizer.

There are scads of other options. Standard fuel is 24 gallons in two 12-gallon wing tanks, but long-range fuel is available (and very popular), resulting in 40 gallons of usable fuel in two wing tanks. It’s the same for the landing gear, which is standard with 6.00×6 tires and fully shock-absorbed gear. A very popular option, fitted to the airplane I flew, was the 3X3 gear—the name connects to the fact that the axles are 3 inches farther forward of the standard gear and 3 inches farther from the airframe, both of which help improve prop clearance. Naturally, there are multiple tire options, from the tragicomically small 6.00x6s to 35-inch tundra tires; the airplane I flew had the popular 31-inch Alaska Bushwheel doughnuts as well as the heavy-duty brakes.

It’s not worth regurgitating the full range of options here, but suffice it to say that you can go pretty wild with your EX-2 CC363i, including with components like a carbon fiber belly pod (to carry cargo or fuel), various interior options, an extended baggage area with door and avionics options. The demo airplane was fitted with a single Garmin G3X Touch screen, GTR 200 com radio and remote transponder. It did not have the optional autopilot. It’s interesting to note that none of the official avionics packages includes an IFR-approved GPS or conventional nav sources.

It was one of those late-summer days in Yakima that promised triple-digit temps later in the day so CubCrafters’ Brad Damm and I got an early start in N18KX. The first impressions of this particular EX-2 fall into line with those of the other CC airplanes, the last of which I’d flown being the NXCub. It’s a traditional shape with just superb attention to detail, especially ahead of the firewall and inside the cabin. Once you’ve mastered the climb-over, climb-around contortions needed to reach the front seat, you settle in behind a simple, clearly marked panel. Brad pointed out that this particular airplane was actually one of the less optioned in the world, with the simpler interior and not a lot of avionics.

I settled in and noted that the visibility over the nose is quite good despite the big tires and taller gear. It’s something CubCrafters has worked hard on and they tailored the seating position as well as the cowling lines to best effect. Engine startup is straightforward. There’s a backup battery supply for the EFIS that you enable before start, and you’ll see a toggle for the emergency backup power to the right ignition system. Like all CubCrafters models, the EX-2 CC363i has dual Light Speed electronic ignitions that are powered by the basic electrical system in the airplane, so the separate backup battery provides a security blanket in case the whole airplane goes down, electrically.

All major switches are arrayed above the G3X Touch display, and the rest of the layout is as expected, with a throttle on the left sidewall below the window, a fuel selector on that same sidewall, non-vernier mixture control on the left side of the panel and a big flap handle hanging from the cage in the upper left corner of the windshield. The ignition switch is over on the right side next to something new for the EX-2, an electric boost pump. That and the absence of a carb-heat knob are about all that tells you this is the injected engine.

Because of the simplicity, run-up is a matter of checking the controls, fuel on the correct tank, checking both ignition systems and setting trim. Once on the runway, the 186-hp EX-2 accelerates very well, though if your frame of reference is the constant-speed-equipped, IO-390-powered XCub, it feels merely excellent where the XCub seems righteously overpowered. With two of us on board, full tanks and a bit of baggage, the demo aircraft was about 200 pounds under max gross. An audio recording of the first takeoff reveals that it took less than 9 seconds to go from power up, stick forward to tail up, maintain a slightly nose-high pitch attitude and to flying. You would expect a fixed-pitch prop to give up some takeoff performance, but the 82-inch Sensenich was pitched for good STOL work, so the engine could turn almost 2600 rpm shortly after takeoff. (I confess that I didn’t see the true static rpm since I was focused on keeping the tail behind us, more an indication of my lack of tailwheel recency than any tendency of the airplane.)

We didn’t sample much of the climb phase, since the airplane was capable of 2000 fpm initially and we weren’t going very high. Remembering that the EX-2 has a lower Vne and other limiting speeds than the EX-3 or the XCubs, it wasn’t surprising to see it venture into the low end of the yellow arc without a big throttle reduction. Finally, to get 2500 rpm, manifold pressure was down to 20 inches (all at 3000 feet MSL) to get 109 mph true airspeed. Owing to the airplane’s status as still in development, we hadn’t leaned much to this stage, but on a subsequent flight it was possible to get fuel flow down near 8 gph with sub-400° cylinder-head temps. (More impressive was the narrow spread from coolest to hottest.)

Which begs the question: How fast would it normally go? CubCrafters is still working the numbers but the CC340-powered version went 110 mph TAS with a fixed-pitch prop while the CC363i and constant-speed on the EX-3 could manage 135 mph. It’s likely there’s a tiny bit of extra cruise in the bigger-engine EX-2, but you’ll need to consider where you use it (low altitude vs. high) as well as how much more prop pitch you want to give the Sensenich and the effect on takeoff and initial climb. Everything is a compromise.

Cubs, modern or otherwise, are never intended to be speed machines. It’s about low approach and landing speeds, superb climb performance (especially the gradient) and a ruggedness that allows them to be used on all kinds of terrain without undue fear of being stranded there. The EX-2 is definitely in the sweet spot. With approach speeds around 50 mph, three notches of big, effective flap—the first two are lift, the last notch is a bucketful of drag—the sub-200-foot landing distances seem totally plausible. Especially once you’ve learned the airplane.

For me, it was more about being smooth and accurate, and the EX-2 made me feel comfortable right off. Handling is predictable and the control forces are moderate—they’ll feel about right if you’re coming from conventional utility aircraft and they’ll feel very heavy if your frame of reference is an RV-7 or -8. But they’re effective and completely predictable. There is a strong pitch-up moment with flap extension that you’ll just have to live with for the few seconds it takes for the airplane to slow, though the simple rocker switch on top of the stick helps trim off those forces quickly enough. It’s more a surprise the first time you feel it than an issue once you’re mind-melded with the airplane. It wasn’t very turbulent nor did we tackle much of a crosswind during our flight, so I can’t speak to that, but the EX-2 was comfortably stable in low-level bumps on a warm day. It’s not a rack-it-around kind of airplane, especially at cruise airspeeds, but you can feel how it has been optimized for the lower end of the envelope—it speaks volumes through control pressures and little signals through the stick. It wouldn’t take long before ignoring the airspeed indicator and starting to fly by tactile sensations alone.

“Honest airplane” is a term overused by aviation writers. But it has resonance here, perhaps explaining why the Cub design has endured and why the CubCrafters version of it has been so successful. At the risk of anthropomorphizing the EX-2, it doesn’t ever seem like it’s trying to do something it can’t and goes about what it does well with a kind of casual regard, a “yeah, sure, I can do that.” The latest EX-2 CC363i version fails to break that feature. And, in some ways, the simple fixed-pitch, modest-power approach feels closer to the Cub ethos than the “ate up with power” XCub. Which the purists will agree with until they’re offered an afternoon with the XCub…

The new EX-2 CC363i is, like all the CubCrafters airplanes, a premium product. Kit prices start at $89,100 for the airframe in three chunks: wing, fuselage and finish kits. The Executive Glass Touch package adds $38,800. Forward of the firewall, the 363i engine costs the same here as it does in the EX-3—$51,745 at press time—but there are cost savings from the propeller, lack of a governor and other variations in the firewall-forward kit. CubCrafters should have updated its configurator by the time you read this, but the essential price difference from the CC340 to the CC363i fixed-pitch is about $20,000. If you were to build your EX-2 just like the factory ship, the total kit costs would be just more than $220,000. If you wanted to create yours as an FX-2, which includes both builder assistance and paint, which the EX does not, you’re looking at between $330,000 and $345,000 comparably equipped.

It’s also worth noting that the fixed-pitch version of the CC363i will be made available on the EX-3 and FX-3 models, giving builders who want the heavier -3 versions a slightly lower-cost firewall-forward package. So it may well be that CubCrafters had to react to a lack of 340 engines coming from Continental, but the resulting effort has pushed the development of the EX-2 and FX-2 just that much further and, luckily, kicked out an airplane that’s exceptionally good at its job.

Watch the walk-around video as Brad Damm details the updates in the EX-2 with the CC 363i engine.

Airframe

Performance

Specifications and pricing provided by the manufacturer. Specs reflect the EX-2 with the fixed-pitch CC340 engine. Performance with the 363 is still being evaluated but is expected to be near the 340’s numbers overall.

This article originally appeared in the January 2023 issue of KITPLANES.

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