That’s the CubCrafters’ NXCub flying high and fast because it has the the lowest weight to horsepower ratio—10.7 pounds to 1—of any production two-place STOL backcountry airplane. Moreover, check out the tricycle landing gear. In a world where insurance companies are walking away from too many pilots who want to fly taildraggers in the backcountry, we think the NXCub solves the dilemma with ease.
Lined up on the runway threshold and holding the brakes, you slide the throttle way forward, over its long travel. The engine sound deepens into an all-encompassing roar as the nose hunkers down a few inches under max thrust. On releasing the brakes the acceleration is turbine-like and all you can think of is the two-word line shouted by the character D-Day in the classic movie “Animal House”: “Ramming speed!”
You were briefed to rotate aggressively as soon as the airspeed came alive, but you blew through that opportunity in seconds. You pull firmly on the stick, the NXCub leaps off of the ground and assumes what has to be a stallspincrashandburn pitch attitude as you try to hold Vx, 59 MPH indicated (the airplane we flew had airspeed in MPH). Oops, you’ve left that speed behind as well. You’re already well above any obstacles, so you continue to pitch up and try to hold Vy, 71 MPH. Nailing it, you realize that it requires a nose-high attitude that you haven’t experienced in a piston-pounder in convenient memory.
While getting the airspeed down to Vy the rate of climb toys with 1500 FPM before settling on 1200 FPM—and you’re loaded to gross weight.
Weight-to-horsepower
Welcome to the NXCub from CubCrafters and the lowest weight to horsepower ratio—10.7 pounds to 1—of any production two-place STOL backcountry airplane. Its impressive performance is a combination of brute force up front along with a sophisticated effort to greatly reduce the drag of an airframe evolved from the Piper Super Cub.
Go Fly
CubCrafters did something that we have not seen in aviation journalism for 50 years—it gave us a brand-new NXCub (the very first of the kitbuilt versions; the others are either Part 23 production airplanes or Experimental owner assist construction) and told us to fly the bejabbers out of it. After checking us out in the flying machine, CubCrafters’ staff pilot David Blake told us to “Bring it back muddy and with grass stains.”
Over the course of two weeks, when the North Idaho weather cooperated, we did just that. We put 19 pilots with experience from just post solo through thousands of hours of bush flying in it and we took it to some spring-weather soggy backcountry airstrips.
Fast Cruise and STOL
Every pilot who flew the NX raved about the STOL performance and surprising cruise speed. Many disparaged its appearance before they flew it and, not surprisingly, the tailwheel purists/snobs decried its nosewheel. After flying it, none said anything bad about its appearance and most expressed appreciation for the nosewheel providing the ability to stop the airplane short without flipping over and the straightforward ground handling.
We’ll go into the unconventional appearance of the NX and the nosewheel/tailwheel issue in a moment. For now suffice to say that the NXCub can be converted to a tailwheel XCub in four hours by two people with the appropriate parts.
We’ll state the conclusion we came to about the airplane right here: The NXCub gives access to serious backcountry flying to a lot of pilots who otherwise would never have the chance to experience it.
Call us reverse snobs if you like, but we think that something that gives more pilots access to more ways to enjoy the world of flight is a good thing.
Performance
It’s powered by what started as a Lycoming IO-390-D3B6 engine redesigned by Lycoming and CubCrafters to create a lighter-weight model now called the CC393i, developing 215 maximum takeoff horsepower and 180 maximum continuous horsepower. The engine is only 10 pounds heavier than the 180-HP Lycoming IO-360. It turns a Hartzell Trailblazer composite prop optimized for backcountry ops.
With that kind of thrust up front, takeoff performance is more than impressive. The POH only gives takeoff and landing distance data for the tailwheel XCub, not the NX. For takeoff over a 50-foot obstacle it’s 974 feet. We think that is conservative because the NXCub gets off the ground in less distance than the XCub due to its lower drag attitude during the initial portion of the takeoff roll.
CubCrafters’ website gives the demonstrated takeoff roll distance for the NX as 120 feet. The best we could do was 200 feet on a calm day from a paved runway at an elevation of 2340 feet, so 120 feet at sea level is probably realistic.
For cruise performance we flew at 7500 feet, running 60 degrees rich of peak: Even with 26-inch bush tires on the main gear, at 75 percent power we observed a TAS of 146 MPH, burning 13.9 GPH; at 65 percent TAS was 140 MPH, burning 11.7 GPH and at 55 percent TAS was 125 MPH with a fuel burn of 9.6 GPH. Going to 50 degrees lean of peak at 55 percent power slowed us to 120 MPH TAS with a fuel burn of only 7.8 GPH.
In a power off, flaps-up stall, the gentle break came at 47 MPH indicated. With the flaps down (46 degrees), the equally gentle break came at 42 MPH indicated.
The POH number for landing over a 50-foot obstacle for the XCub is 1580 feet. We think that is more than conservative. The POH also calls for 60 MPH indicated with full flaps on final. We think that’s too fast as 55 MPH is 1.3 Vso, a normal final approach speed. Power off, with full flaps and the fat prop at the low pitch stop, the NXCub comes out of the sky like your favorite cliche. Our experience landing over an admittedly estimated 50-foot obstacle got us down and stopped easily in under 1500 feet. Using STOL landing techniques of approaching at 1.2 or 1.1 Vso would lessen the distance.
David Blake told us that we could touch down with the brakes locked and the nosewheel would handle the load while maintaining plenty of prop clearance from the ground. The CubCrafters website says the minimum demonstrated ground roll is 80 feet.
We admit it, we couldn’t bring ourselves to touch down with the brakes locked. On grass we did lock up the brakes almost immediately after touchdown. The tires slid, reducing friction (no antiskid brakes), and we were able to stop in less than 400 feet.
On pavement we went to the point of hearing the tires squeal, but not wanting to erase them, we backed off. We could stop in just over 200 feet at gross weight.
Systems
CubCrafters started life rebuilding Piper Super Cubs. Founder, the late Jim Richmond, soon decided to build a better Super Cub—first via STCs and then through modern, stronger and lighter airframe components such as carbon fiber to create a complete airplane.
The result was a series of lighter, more robust versions of the Cub and Super Cub. After a six-year secret development program CubCrafters marketed its top-of-the-line XCub—both as a builder-assist Experimental and Part 23 production aircraft.
In 2020 the nosewheel NXCub version was marketed and power was boosted to 215 HP. This year the kit Experimental version came out.
The NX has 44.6 gallons of usable fuel in wing tanks. The fuel selector is located on the left sidewall and has off, left and right positions. Because the engine is fuel-injected, FAR Part 23 prohibits the engine from being able to draw fuel from more than one tank at a time.
The nosewheel is free castering through 95 degrees so steering on the ground is with the brakes. The NXCub can pivot on one wheel as with tailwheel airplanes.
The stop on the nosewheel can be removed in about five seconds to allow the wheel to swivel through 360 degrees. We found it handy for pushing the airplane backward into parking without having to use a tow bar. Because the prop can hit the tire with the nosewheel backward, there is a red light on the panel to notify the pilot that the nosewheel stop is not installed. Engine startup in that condition is prohibited. Installing the stop took us five seconds.
The nosewheel is a part of the engine mount, rather than the weaker firewall as is otherwise common, and the strut is mounted as far forward as possible. It has a trailing beam shock absorber that is not only beefy as heck, but the hinge location effectively makes the nosewheel diameter larger than its 6 x 800 tire, allowing it to roll over good-sized ruts and handle rough runways while protecting the prop.
The one-piece aluminum main landing gear is gun-drilled to allow the brake lines to run through it, protecting them from being cut by obstructions found on backcountry strips and keeping them out of the wind where they would add drag.
The ailerons are pushrod activated, making operation very smooth.
Elevator trim is electric, controlled by a switch on the stick. A motor drives a jackscrew that moves the leading edge of the horizontal stabilizer.
Nosewheel/tailwheel
In the decades of publishing the Used Aircraft Guide as a section of this magazine each month, one thing that we’ve learned is that no matter how experienced tailwheel pilots are, they wreck their airplanes on landing at a rate from two to three times as frequently as pilots in nosewheel airplanes. They also flip their airplanes on landing with distressing regularity. No matter how many times tailwheel pilots assert, correctly in our opinion, that learning to fly tailwheel improves a pilot’s skills, the accident record—and insurance rates—speak volumes.
CubCrafters’ personnel told us that they found their market limited if they didn’t offer a nosewheel airplane. As Cessna and Piper learned in the 1950s, nosewheels mean more pilots will buy airplanes and fly them.
Cessna also demonstrated with the 208 Caravan (which was originally intended to be a tailwheel machine, but prospective operators said that they couldn’t find pilots) that an airplane with a seriously beefed-up nosegear can go into the backcountry without breathing hard. The Peterson Performance canard conversion of the Cessna 182, now the super-STOL King Katmai, with its heavy-duty nosewheel can go anywhere a tailwheel airplane can. Besides, a rough runway can break off a tailwheel. Ask us how we know.
Yeah, we’ve heard all the comments about the NX being ugly. In fact, when we were at one backcountry strip, a Super Cub pilot was barely even polite to us.
Are we that superficial when it comes to appearance over functionality? Don’t answer.
In our opinion, not only is the NXCub cheaper to insure than its tailwheel counterpart, its kindly ground handling and overall ruggedness mean that a lot of pilots who otherwise would never fly safely in the backcountry now can. That’s what we think is important. It’s not worth arguing aesthetics.
Weight and Balance
Using modern technology, CubCrafters wanted to build a 1000-pound useful load backcountry airplane. They succeeded. The NXCub will carry a staggering load, even the one we flew that had virtually every option, which reduced its useful load to 855 pounds. That’s still full fuel, two big occupants and a bunch of stuff.
There’s a catch. The loading envelope is weirdly shaped, in our opinion. Loading to the max gross weight of 2300 pounds is only allowable at or near the max aft CG location. At the forward CG limit, max gross is only 1690 pounds, giving a useful load in the airplane we flew of but 245 pounds.
The solution is to take advantage of the two large baggage areas. The forward can hold a whopping 180 pounds, the rear 50. To carry full fuel means also carrying something in one or both baggage areas to stay in the loading envelope.
For us, going into the backcountry means carrying survival gear and tools. Fortunately, the NXCub will carry the weight and essentially encourages you to bring that gear to stay within the loading envelope. Nevertheless, we are concerned about how easy it is to load the airplane over gross at forward CG positions.
Fit and Finish
In a word, the quality of the $549,500 airplane we flew was outstanding. We couldn’t find a flaw in the paint or interior furnishings. In addition, there are an astounding number of small storage areas throughout the interior.
Unlike most two-place backcountry airplanes, the NX airframe is sleek. There are only a few bits, such as small hinges, sticking into the airstream. The wing struts and fuselage are aerodynamically cleaner than any airplane we’ve flown in this class. Some care went into the design and building of the airplane we flew.
Avionics
It’s no longer weird to talk about advanced avionics in a bushplane. With the advent of the glass panel and the saved weight involved with getting rid of gyros and a vacuum pump, we’re routinely seeing amazing avionics in bushplanes.
The NX we flew had the Garmin G3X touchscreen suite with dual-axis autopilot. We found ourselves taking advantage of the functionality of the G3X and using the autopilot to let us look around without distraction when letting down toward a backcountry strip.
Handling
In a word, delightful. A number of the pilots we put in the airplane liked the handling so much they asked whether it was aerobatic. No, sadly, and spins are prohibited.
Steep turns were great fun and slow flight utterly solid. Differential travel of the ailerons means that there is substantially less adverse aileron yaw than on other small bushplanes, but a pilot still has to learn how to use the rudders.
There is a lot of pitch change with flap extension and retraction, which gave some low-time pilots initial difficulty, but they adapted quickly.
Coming down final, on speed, in gusting winds was work due to the relatively low wing loading, but there was never a question of having adequate control. The demonstrated crosswind component is 11 MPH. It seemed low—we liked how the airplane handled crosswinds.
Go-arounds from even deep in the flare were surprisingly easy because of the sheer power available and the surprisingly small amount of right rudder required.
Pilot reaction
We saw a lot of large smiles as pilots got out of the NX. Low-time pilots were initially overwhelmed by the acceleration on takeoff; they admitted to sensory overload, but soon adjusted. All liked the handling on landing and rollout, even in gusting crosswinds.
The high-time backcountry and forestry pilot did some simulated animal tracking at 200 feet above the trees in mountainous terrain and marveled at how little power was required to hold the slow speed he desired. He commented that with the power available that the NX was the best airplane he’d ever flown for wildlife and fire surveillance.
Conclusion
We think CubCrafters has created a winner in the NXCub because of its sheer performance and its ability to bring more pilots to some of the most beautiful and fun flying there is.
