Ugly duckling becomes a swan
Amphibious floats make the NXCub gorgeous
A golden evening in the Adirondack Mountains of upstate New York provides ideal flight and water conditions for this muscular 215-horsepower NXCub on metal Wipaire 2100 amphibious floats. It’s the largest, most powerful, and most capable FAA-certified amphibian that CubCrafters has ever produced.
“The heart of the NXCub is its Lycoming [CC393i] engine,” said Mark Keneston, CubCrafters sales manager for the Northeast, who learned to fly on this lake as a teen in his dad’s float Piper J–3 Cub. “That engine and a two-blade, constant-speed Hartzell composite prop give the NXCub speed, long range, and the ability to lift heavy loads off runways or water.”
The nosewheel NXCub was—and among backcountry purists always will be—the ugliest of ugly ducklings. Its 2020 introduction was deeply polarizing among loyal CubCrafters customers who expressed an “Et tu, Brute?” sense of disbelief that the company long regarded as a guiding light among Super Cub afficionados had driven a dagger through the heart of tailwheel traditionalism.
On amphibious floats, however, the NXCub isn’t ungainly anymore. It stands tall, proud, and proportional on its four tires. The ugly duckling has become an elegant swan.
Jungle gym
Up front, the long, 83-inch propeller and massive air intakes hint at the high power, and high heat, the NXCub engine puts out. A shiny metal muffler protrudes from the air outlet at the bottom of the cowl instead of the straight exhaust stacks on other Carbon Cub models.
Wipaire 2100 amphibious floats have long set the standard on PA–18 Super Cubs (as well as the FAA-approved Top Cubs CubCrafters used to produce). So, the rugged, flat-topped metal floats made in Minnesota are a known quantity. The float kit includes a long ventral fin below the tail for yaw stability. A vertical fin on top of the fuselage that’s common to all NXCubs accomplishes the same purpose.
The passenger door is on the left side of the fuselage, and a large top-hinged window is on the right. Climbing into the airplane is like mounting a jungle gym. The multipart process begins by putting a foot on the recessed step on the outside of the left float and vaulting up onto the float itself. Then climb onto the long, grooved step in the rigging, seat yourself on the cockpit rail, and swing both legs inside. Steel bars at the front of the cockpit are convenient for pulling yourself onto the front seat.
Once inside, the cockpit is spacious, refined, and ergonomically excellent.
Visibility over the nose is expansive because of the airplane’s commanding height and level attitude. The cloth seat (leather is an option, but who wants leather seats in a floatplane?) is firm yet comfortable with a memory foam core. The seat adjusts fore and aft, and rudder pedals with toe brakes are fixed.
The instrument panel has a Garmin G3X primary flight display/multifunction display as its centerpiece with digital engine gauges on the right side of the screen. A Garmin G5 standby instrument serves as a backup on the left side of the panel, and the Wipaire landing gear advisory system is on the right.
The fuel selector is on the left cockpit wall, and it has Left, Right, and Off positions but—surprisingly for a high-wing airplane—there’s no Both setting.
The throttle, prop, and mixture levers are on the extreme left side of the cockpit, and switches are logically laid out. Starting the engine means moving across the panel from left to right with battery, alternator, electronic ignition, and electric fuel pump switches activated in the proper order. Then turn the key on the right side of the cockpit to spin the propeller.
The front wheels are free-castering so taxi turns require differential braking. Pedal pressure while taxiing is moderate to heavy. Runup is standard for a fuel-injected engine, and the digital gauges and graphical, color-coded bars with built-in warnings provide a great deal of information in a format that’s familiar and easy to understand.
Taking off from a hard-surface runway resembles a soft-field takeoff in a tricycle-gear airplane: Apply full nose-up elevator and full power. When the nosewheels lift off the ground, reduce back pressure and maintain the wheelie. Keep a positive angle of attack and let the main wheels lift off when they’re ready.
Acceleration during the ground roll is moderate, and the NXCub with half fuel, two dudes, and about 20 pounds of gear lifts off in about six seconds at 52 knots. At about 50 feet agl, I raise the landing gear handle and watch the four green lights indicating the wheels are down extinguish and four blue lights signifying the wheels are up illuminate. Mechanical Up/Down indicators are visible on top of the floats; there’s a mirror on each strut to check whether the wheels are in the proper position for runway or water landings, and the gear advisory system provides aural warnings.
Cylinder head temperatures and exhaust gas temperatures remain within normal limits during the short climb to 2,500 feet and the NXCub makes the 15-nautical mile transit to the Great Sacandaga Lake at 104 KIAS at 75 percent power while consuming 11 gph.
Floatplanes tend to wander in yaw, but the NXCub is rock steady in that axis. There’s a small but noticeable amount of adverse yaw when briskly rolling into turns so some rudder is required for coordination, and the float NXCub is slightly heavier in pitch than roll. Lively ailerons are a CubCrafters hallmark and the NXCub on floats shares that delightful family trait with a maximum roll rate of about 45 degrees per second.
Slow flight is steady and predictable. The engine/prop combination provides quick acceleration and deceleration and allows for especially precise airspeed control. In level flight at idle power with flaps retracted, full back stick produces a mushy descent at 48 KIAS without a stall break. Adding flaps allows for a crisp stall break at about 33 KIAS with symmetrical wing drop. Stall recovery is immediate as soon as the wing angle of attack is reduced.
Keniston advises 65 KIAS and two notches (30 degrees) of flaps for water landings, and I follow his recipe. At 70 KIAS in level flight, I reach for the flap handle on the upper left edge of the canopy, depress the trigger, pull, and feel the nose pitch up slightly as the flaps droop. The electric trim switch at the top of the control stick is set to maintain 65 KIAS. I carry a smidge of engine power into ground/water effect, hold a 10-degree nose-up attitude, and work the stick aft as the airplane decelerates.
The keels on the rear halves of the floats touch down at 42 KIAS and I pull the throttle to idle and apply full back stick as the floats settle into the water.
My first landings take place near the middle of the expansive lake where a steady wind estimated at eight knots creates six-inch waves. I lower the water rudders via a chain on the right side of the cockpit, and steering is positive. Downwind turns can be made at idle power, and pedal pressure is moderate to heavy, just as it is on land.
Taking off from the water is the NX’s superpower. With the prop in fine pitch and one notch (15 degrees) of flaps, the pilot applies full back stick and full engine power. The engine seems to reach maximum rpm in about three seconds, and the nose rises immediately.
It takes about four seconds for the floats to get on the step, and that’s the pilot’s cue to reduce elevator back-pressure. The airplane holds a roughly 8-degree nose-up attitude as it accelerates, and it’s ready to fly at 44 KIAS about 12 seconds after applying full power at the start of the takeoff run.
The NXCub ailerons become effective at about 25 KIAS, and the pilot can reduce surface friction by “rolling a float” at about 35 KIAS. That technique seems to shave about two seconds from the takeoff run.
Docking, beaching, or ramping the NXCub is indistinguishable from other airplanes equipped with Wipaire 2100s. The NXCub’s single side door can complicate docking since the only way for airplane occupants to reach the left float is walking the cable at the front of the floats, and that’s especially fraught immediately after engine shutdown when the cowl is sure to be hot.
The rear seat is a fabric sling that’s exceptionally light and easy to move out of the way when loading or unloading gear.
My suggestions for the NXCub are few: Move the landing gear advisory system to the left side of the panel to make aural advisories easier to acknowledge (and silence). Add a lightweight, solid state, Garmin radar altimeter to assist in glassy water landings. And make terrain warnings easy to inhibit without having to dig deep into G3X sub-menus.
Customer acceptance
As an FAA-certified airplane, the NXCub is meant to appeal to owners of aviation businesses with commercial operations, government agencies, and recreational customers who won’t consider the experimental-category airplanes. The NXCub is also likely to attract foreign buyers in countries that only recognize FAA-approved aircraft.
CubCrafters originally certified the tailwheel, 180-horsepower XCub in 2016 after a secretive, six-year process. The company based in Yakima, Washington, was already planning for a nosewheel version even then. But the process of engineering and certifying a nosewheel that was rugged enough to perform in the backcountry, didn’t create excessive drag, and stayed out of the way of the engine was more complex than anticipated. Designers came up with the CC393i largely to meet the needs of the new nosewheel assembly.
Although the initial reaction to the NXCub was mixed, its adoption in the marketplace has been overwhelmingly positive. CubCrafters began selling experimental NX versions in 2020 and the FAA granted certification in 2022, and for the past four years nosewheel NXCubs have outsold tailwheel XCubs.
In side-by-side comparisons, NXCubs have shown they can take off and land as short as tailwheel models. And the more powerful CC393i makes NXCubs fly faster in cruise. They’ve also opened backcountry flying to pilots who haven’t spent many years and thousands of flight hours mastering tailwheel skills, and insurance rates for nosewheel airplanes are less costly.
And it turns out enlarging the market for backcountry flying is the NXCub’s whole reason to exist. Tailwheel purists, it turns out, are a vocal and shrinking minority.
Sense of connection
My main impression after several flights in the float NXCub on water and land is how quickly a pilot feels connected to it.
The airplane’s rare combination of stability, responsiveness, predictability, and grace makes it feel like an extension of you during your first flight hour together. Want to touch down at the mouth of the sandy cove by the marina? Simply point the nose where you want to go and minor pitch and power adjustments fine tune your flight path along the way.
Want to lift off a bit sooner during the takeoff roll? Simply pull on the flap handle and feel the floats rise from the water.
When flying the float NXCub, your focus is outward and the act of operating the aircraft becomes second-nature. You do it without thinking about it, and that inspires confidence in the air and on the water.
Since returning home, my mind has been filled with the possibilities for the adventures that such a remarkable airplane puts within reach. Alaska? Arctic Canada? Greenland? Iceland? The Bahamas? Caribbean? Patagonia?
Any, or all, of these places are suitable playgrounds for the NXCub.
