I used to have a buddy in the drag-racing business who claimed that given enough horsepower, you could push a Peterbilt through the Mach in a quarter mile. That’s perhaps a little extreme, but there’s no question horsepower solves (and creates) a number of problems associated with motorcycles, cars, boats and airplanes. Back in the ‘60s and ‘70s, I watched Lyle Shelton build his surplus F8F Bearcat race plane Rare Bear in the hangar next to mine at Compton, Calif. There was no question that more power was high on the list of gotta-haves.
Lyle replaced the Bearcat’s P&W R-2800 engine with a huge Wright R-3350, and in combination with water injection, higher turbo boost and a number of other tricks, Lyle claimed the engine
was churning out well over 3,000 hp. I never found out if that was an actual dynamometer readout or just a dream, but he did have remarkable success with the airplane on the air-racing circuit—six national championships.
Such raw power may also be a key to Rare Bear’s world time-to-climb prop/piston record (91.9 seconds from sea level to 3,000 meters—9,843 feet) and its three-kilometer propeller speed record (529 mph).
The folks at CubCrafters in Yakima, Wash., don’t have any such grand plans for their Carbon Cub SS, but the airplane certainly is the most enthusiastic LSA you’re liable to encounter. Though CubCrafters’ Carbon Cub (previously known as the Super Sport Cub) is saddled with the same 1,320-pound gross weight limitation as on other LSAs, the airplane sports an impressive 180 hp, the most powerful engine in the class. The Carbon Cub’s engine is a new modified mill known as the CC340, developed by ECi of San Antonio, Texas, and CubCrafters, specifically for application to the Carbon Cub product.
The SS’s motive force is a variation on the famous Lycoming O-360 powerplant, with special emphasis on weight reduction.
Accordingly, the CC340 engine has an all-up weight of only 242 pounds. It features a lightweight CATO composite propeller, 40-amp alternator, a purpose-built ultralight starter and electronic ignition. The result is 35-50 pounds less weight on the nose compared to a standard O-360 Lycoming installed in a Piper Archer or in CubCrafters’ own Top Cub. Unlike the Lycoming 360, the CC340 develops its full 180 hp from only 340 cubic inches of displacement.
In addition to lighter weight forward of the firewall, the SS features remarkable weight reductions in other areas. In contrast to the Super Cub, the Carbon Cub contains 50% fewer parts, and the total airframe is 250 pounds lighter than its Piper predecessor. The fuselage is of 4130 aluminum, and the wing is the traditional Piper USA35B airfoil.
CubCrafters offers several instrument panel configurations for the Carbon Cub. Pictured above is the Deluxe VFR Panel, with a Garmin 496 (that can be replaced with a Garmin aera 550 for pilots who prefer a touchscreen interface), Garmin 327 GTX transponder and Garmin SL40 Comm. The Executive Glass Panel option includes a Garmin GDU 370 and Dynon EFIS.
Thanks to CAD (Computer Aided Design) engineering and extensive use of lightweight/high-strength carbon-fiber parts rather than wood or aluminum, the Carbon Cub SS scores a low 900-pound empty weight against a 1,320-pound max gross. This leaves 420 pounds of useful load, the result of significant weight savings in the wings, fuselage and forward of the firewall.
Most of the time additional cabin space doesn’t weigh much, and accordingly, the SS sports a wider, more comfortable cabin than the original Cub. Specifically, the cabin is four inches wider at the shoulders, and the panel is pushed four inches farther forward.
Despite its light weight, CubCrafters’ ultimate LSA doesn’t suffer any loss of strength to other airplanes in the class. In fact, it has actually been tested to part 23 standards, 1,865 pounds—40% above normal LSA limits. The carbon-fiber material used so extensively in the airplane’s construction contributes to a stronger airframe and wing structure. Perhaps in keeping with the name, carbon fiber is used in a variety of interior and exterior parts.
The Carbon Cub still manages to retain its Cub personality, but no matter how many hours you have in the original Piper, you know the ride in the SS will be special when the throttle goes against the forward stop. The response is immediate and gratifying. Power loading is one sure measure of a given airplane’s potential takeoff and climb performance—the lower, the better.
In the case of the Carbon Cub SS, each horse is powering only about 7.3 pounds of airplane. Compare that with other general aviation airplanes, and you’ll note it’s one of the best power loadings of any personal/business aircraft on the market.
Among certified models, the Extra 300 and Pitts S2C score power-to-weight ratios below 7 pounds per horsepower, two of the few airplanes with a lower power loading than the Carbon Cub. CubCrafters’ own certified Top Cub uses a similar 180 hp Lycoming against a gross weight of 2,300 pounds to record a power loading of 12.8 pounds/hp.
Numbers can drive you nuts in this business, but they’re necessary evils. The point is that the Carbon Cub SS is one of the most enthusiastic short-field airplanes on (or in this case, above) the planet. The SS scores among the best takeoff numbers of any flying machine without a rotor overhead.
The result of the horsepower upgrade and weight reduction is a climb rate you might more typically associate with a corporate turboprop. The Carbon Cub SS leaps off the ground in less than 200 feet and scores an initial 2,100 fpm uphill from sea level. The 180 hp rating is good for five minutes.
This suggests near-helicopter capability. It’s very likely the Carbon Cub SS could duplicate the near impossible, semi-vertical climb performance of a Helio Stallion. Years ago at the Alaska Airman’s Association Convention in Anchorage, I witnessed the Helio’s simulated box-canyon climb demonstration.
Imagine the airplane is at the bottom of a box canyon that’s no more than, say, 500 yards on a side. (Never mind how it got there.) The pilot lines up along the longest axis, goes to full power, releases the brakes, runs less than 100 feet, rotates hard and almost immediately rolls into a 45-degree bank in either direction at an airspeed of 40-50 knots. He then maintains that tight rate of turn and gradually corkscrews up and out of his box canyon. The Helio pilot didn’t suggest anyone had actually used this technique in a REAL box canyon (again, how would you get there?), but it certainly makes an impressive demonstration.
As you might imagine, identifying cruise performance on the Carbon Cub SS is simply a matter of acknowledging the top speed limit set by the FAA. Max cruise has been set at 120 knots by simply limiting cruise power to 80 hp, about 45% of total rated power.
One benefit of the low power setting is that it results in a proportionately low fuel burn. At an estimated sfc of .42 lbs/hp/hr, consumption works out to 5.5-6.0 gph. With 12 gallons in each wing tank, and head pressure sight gauges in each wing root to identify the level, you can linger aloft for three hours plus reserve, probably enough for most people.
Cruising at the speed limit of 120 knots means you can plan on 300-350 sm range, if that’s your mission, and of course, there’s no reason to use economy cruise as you’re already there. Visibility is excellent from either seat.
The Cub does its best work in short-field mode. One reason is the big flaps, deployed logically enough by a lever at top-left cabin. The flaps extend to 50 degrees, and you can imagine what that does to stall speed. Another is the Boundary Layer Research Vortex Generators. These re-energize the boundary layer on the top trailing edge, reduce stall slightly and actually enhance aileron control at the lower edge of the envelope. There’s nothing negative about them (except that they probably do make the airplane a little harder to wash).
Even with 29-inch tundra tires mounted, you can fly final at whatever speed you feel comfortable, down to probably 40 mph. Dirty stall is about 31 mph, so 50 will work well as a conservative number. I had a buddy in Alaska years ago who used to fly his Super Cub at such a slow speed on final, the airspeed needle was bouncing around the bottom of the dial. He was actually flying in the stall, not a trick for the faint of heart.
I’m not that good, so I stuck to 50 knots as a typical approach speed. Flying with CubCrafters General Manager Randy Lervold, I did about a half-dozen landings, and despite my rusty taildragger technique, the airplane lived up to its name, a Cub. It was gentle and forgiving in every mode, and though I didn’t try a max-performance, slam-it-down-and-stomp-on-the-binders effort, it’s apparent the Cub SS easily could land and grind to a halt in 300 feet or less.
There are probably a half-dozen airplanes that nearly always incite a case of the gotta-have-its when I fly them. An Aerostar 700 is one, an Extra 300 is another, a Lake Renegade is a third. There are several others, but the Carbon Cub SS is a new addition to that list.
I know it could be a great working airplane for hopping around the boondocks of Canada and Alaska. Personally, if a factory built a Carbon Cub SS S-LSA, I’d use mine strictly for fun.
Short-field flying in Alaska is often as mandatory as it is voluntary. While Alaska has a reasonable selection of paved or prepared runways, it’s primarily a place where pilots must make their own way.
Paul Claus of Chitina, Alaska, is one of the foremost bush pilots in the Last Frontier. He has over 20,000 hours of bush experience, much of it in the venerable Super Cub.
At the recent Valdez Fly-In this May, Claus flew a stock CubCrafters Carbon Cub SS to victory in the Alternate Bush Class of the STOL competition. He took off in 64 feet and landed in 69 feet with no wind. Three years ago, he flew the prototype Carbon Cub and posted a helicopter-like takeoff run of 19 feet (with the help of a little wind).
Flying The Inside Passage
By Jessica Ambats
The glaciers, fjords and remote islands that define the rugged coastline from Puget Sound through southeastern Alaska are an aviator adventurer’s dream come true. It’s the kind of place that makes you want to set up camp and disappear for a long time. In May, I joined CubCrafters demo pilot Pete Vinton on a portion of his journey in a Carbon Cub SS from Valdez, Alaska, to Yakima, Wash. We didn’t have a long time and we didn’t have camping gear, but we did have perfect weather—a rarity for the Inside Passage—and we had a perfect airplane for the mission.
In fact, our airplane was a champ! A few days prior, veteran bush pilot Paul Claus had flown Five Papa Charlie to victory at the legendary STOL competition in Valdez, where the best take off and land in ridiculously short distances. And so, armed with life vests, extra containers of 100LL and a bunch of energy bars, we launched from Alaska’s capital, Juneau, on a clear, calm Monday morning.
Juneau-Ketchikan, 2.5 hrs
Mendenhall Glacier isn’t on our direct route, but we overfly it anyway, just because. It’s immense. We circle a Siberian husky dogsled camp and spot mountain goats perched upon steep, rocky terrain. Turning south, the buildings and cruise ships of Juneau fall out of sight and within minutes we’re in another world, ensconced in a spectacular wilderness. To the left are massive snowcapped mountains and secluded turquoise lakes. To the right, the Pacific Ocean sparkles. We open both windows and take it all in.
CubCrafters demo pilot Pete Vinton, who also flies Boeing 777s for United Airlines, explores a sandbar in the Hecate Strait near Prince Rupert, British Columbia.
Ketchikan-Prince Rupert, 1.2 hrs
Sheer rock walls rise from the shoreline, and our wandering route crosses over a lengthy stretch of water where we catch a glimpse of a gray whale. After touchdown in British Columbia, we learn that the Canadian customs agent has left for the day. But with a quick call we’re on our way again.
Prince Rupert-Bella Bella, 3.3 hrs
A solitary sandbar in the Hecate Strait begs for the Carbon Cub to visit. We oblige. Nearby, sea lions observe with idle curiosity as our 26-inch tundra tires greet the pristine sand. We shut down the motor and notice a large bald eagle perched upon the weathered branches of a fallen tree. The stoic bird is in its element, and so is the Cub.
Bella Bella-Port Hardy, 1.0 hr
In a race against the sun, we land to a crimson northern sky and walk to the Airport Inn. I use the web browser on my cell phone to file our eAPIS manifest for tomorrow’s trip, as required by U.S. Customs.
Port Hardy-Tofino, 2.8 hrs
The morning weather is still fairytale perfect, so we head west to explore the Pacific coast of Vancouver Island. Dozens of coves and inlets offer landing opportunities on sheltered beaches that would be unavailable to most other aircraft. Sand flings in all directions as we rudder around a tight curve on the first rollout of the day. The dramatic setting makes it difficult to resist a few more landings, so we don’t. But when we finally continue south, hardly three minutes pass before another lonely stretch of sand catches our attention. It’s about time to check the oil anyway, we tell ourselves, and so we justify a touchdown on the sloped shore lined with pine trees as a “maintenance stop.” The next landing site has its own personality, as does the next (and the next), and our champ handles each like… a champ. But time is running out, and it feels tragic whenever we pass an awesome beach without stopping.
Tofino-Seattle, 2.1 hrs
The air cools rapidly in the ascent over Olympic National Park. Puget Sound appears over the cowling all too soon and my eyes are sore at the sight of “the real world.” We land at Boeing Field, where two brand-new 787s sit on the ramp. Reluctantly, I pull my bags from Five Papa Charlie and part ways with the Little Cub That Could. Pete departs on the final leg to Yakima and I schlep to SeaTac.
Seattle-Los Angeles, no longer counting
The abrupt transformation of today is surreal. From the front of a fire-breathing, backcountry-dominating Carbon Cub and a view of all things wilderness to the back of a full 737 airliner and a view of—I distract myself by writing in a notebook: To-Do List for Next Year’s Trip: 1. Pack a tent; 2. Land on the beach next to the rain forest; 3. Land on the beach with the pounding surf; 4. Land on the beach….