Just Aircraft’s SuperSTOL Extreme: Economy Class, STOL Performance

You might think the feds' limitations---two seats, fixed-gear and fixed-pitch (or ground-adjustable) prop, 1,320 pounds gross weight, a max 120-knots cruise and 45-knot stall---would automatically constrain designs to fairly simple limits.

You'd think wrong. It was perhaps inevitable that LSA designers would look for methods to improve their designs without violating the rules, and a number of the survivors in the LSA movement have done exactly that.

At one time, there were more than 100 companies vying for the LSA dollar. Today, that number has been cut in half, but the remaining contenders have demonstrated that they understand the market, though it's likely there will still be some fallout in light-sport manufacturers.

Inevitably, there have been a number of Cub semi-clones. Because of its light weight, the stock J-3 Cub is allowed to operate as an LSA, as well as a certified CAR-3 production aircraft. The J-3 complies with all the federal requirements for light-sport operation, and in some places, semi-original J-3s are still available for rent as either LSA or production aircraft.

Anyone who has flown a real J-3 will be happy to brag about its considerable talents, and they'll probably mention a few of its shortcomings, as well. For that reason, the basic Cub became a good starting point for building a better short-field taildragger.

Be advised, the Just SuperSTOL (SSXL) ain't a J-3 clone. The tendency is to call any two-seat, high-wing taildragger a Cub clone, but the Just Aircraft SuperSTOL XL is actually a whole different breed of flying machine, owing virtually nothing to the Cub. About the only real resemblance is the tailwheel, and even that's far removed from the Cub configuration. The Just improves on every performance parameter established by the venerable Super Cub way back in the early 1950s.

One of the most obvious upgrades is the option of more power. Piper's initial Cub began life with an underwhelming 37 hp. This was upgraded to 40, then 65, then 85, 95, 105, 115, 125, 135 and eventually 150 hp. For that reason, it's sometimes hard to find a completely stock Cub. Most have been fitted with larger engines as they've reached TBO.

Like so many kids of the 1950s, my first lightplane ride, at age 13 in Anchorage, Alaska, was in a Civil Air Patrol, 85 hp, "Super" Cub. I "logged" about 20 hours riding in the back seat and saw firsthand what the little airplane could do, flying on wheels, skis and, believe it or not, floats.

The top production Super Cub featured a Lycoming O-320 that cranked out 150 hp. The Just SSXL is a side-by-side two-seater that raises the bar even further to 180 hp.

In keeping with his airplane's model designation, designer Troy Woodland configured the Just SuperSTOL XL ("XL" stands for extra long) with a 21-foot, six-inch fuselage, a full two feet longer than his original Highlander model of several years ago. To partially compensate for the cabin and tail stretch, Woodland pushed the cowling six inches farther forward to accommodate the ULPower UL520 180 hp engine and still preserve the CG. For those seeking truly King Kong performance in a bush-capable airplane, the ULPower engine is top of the line.

If you're looking to truly dazzle your friends and intimidate your competition, you'll want the 21-inch or 29-inch tundra tires that allow the Just SSXL to take on fairly rough strips without undue concern. In fact, even larger tires can be mounted, but at some point, weight becomes a consideration.

One interesting point about any of the bush tire options: They can serve as impromptu floats that allow you to land in a river or lake, water taxi to the shore, chop the throttle when you hit the beach and lower the tail to the rocks. Just remember to keep your speed up when you're water skiing, so the airplane doesn't sink.

The SuperSTOL employs leading edge slats that begin to deploy asymmetrically as the airplane slows through 40 mph and helps impart talents you wouldn't imagine possible unless you see the airplane in action. Leading edge slats have been enhancing aircraft performance since at least WWII. Germany installed them on their first-line fighter, the Me109, in the late 1930s. This allowed Luftwaffe pilots to pull harder and maneuver more aggressively during dogfights, providing advantages over Allied fighters with fixed leading edges.

After the war, the Russian Antonov AN-2 Colt, allegedly the world's largest single-engine airplane, also mounted automatic slats that allowed the Colt to slip into miniature non-airports in Russia's hinterlands where improved runways are a rarity. Though Colts are now long since out of production, thousands were built under license in a dozen countries, and even today, AN-2s earn their keep transporting people and things to unlikely places.

The SuperSTOL XL utilizes virtually every aerodynamic and short-field trick available to fly takeoffs and landings in heart-stopping distances. The 132-square-foot, metal-covered wings are fitted with VGs (vortex generators), the flaps are huge Fowlers that translate aft as they deflect down to 40 degrees, and as mentioned above, Just also incorporates automatic leading edge hydraulic slats to allow short-field performance only slightly less than that of a helicopter. Additionally, the wing features aileron-activated spoilers to improve low-speed response and further reduce stall.

Each main gear features a long hydraulic shock absorber that will depress a full 12 inches to cushion a hard landing. The gear struts themselves are designed to bow out as much as 21 inches at the axles to further absorb landing loads. Even the tailwheel, often a weak point on conventional-gear airplanes, has a hydraulic shock absorber.

All this technological innovation allows the Just SuperSTOL to do amazing things in short strips. It also provides climb rates as high as 3,000 fpm, and full flap stall comes at a ridiculously low 32 mph.

I flew with Just factory test pilot and Alaskan bush pilot Harrison Smith out of the abbreviated ultralight/lightplane grass runway at the 2015 EAA AirVenture Oshkosh. There were two SuperSTOL demonstrators flying almost continuously at the show, but their flight demos were limited, as the top of ultralight pattern was 300 feet AGL to avoid conflicting with incoming Oshkosh traffic. Still, Smith was able to show off the airplane's impressive climb and short-field capabilities, probably 150- to 200-foot takeoffs and less than 100-foot landings.

The Just features a wide, tall, comfortable cabin with a large skylight overhead that allows you to look into turns and spot traffic on the ground or in the sky. The airplane comes standard with a tailwheel lock to keep the nose pointed forward during the takeoff run, a major point if you choose the 180 hp UL 520 option. A 1,320-pound airplane with 180 hp on the nose has a power loading of only 7.3 pounds/hp and an appropriate amount of torque to demand a heavy right pedal on takeoff.

A max-performance landing demands a high angle of attack (roughly 25 degrees), and an aircraft carrier-style kerplunk landing with the tail touching down first and the mains following a second later.

Woodland designed the Just SSXL with folding wings to allow storing it in any available space. Total width with the wings folded is eight feet, six inches, the maximum allowed for towing on the nation's highways.

Since the SuperSTOL XL's debut at Sun 'n Fun this spring, Just Aircraft has produced 20 SSXL kits. LSA kit price is $38,900, but Woodland and his partner, Gary Schmitt, hope to certify a special LSA (S-LSA) factory-built model soon, so you'll be able to travel to Walhalla, S.C., fly away with a complete airplane and never have to turn a wrench.

Oh yes, Smith reports that max cruise is about 110 mph, in case anyone cares. Personally, I'd be having so much fun jumping in and out of 400-foot strips that I probably wouldn't even consider cross-country flight. That is, after all, consistent with the company's name and slogan, "Just Plane Fun."

For more information, please contactJust Aircraft, Walhalla, South Carolina, Tel: (864) 718-0320, Email: contact@justaircraft.com. On the web at www.justaircraft.com.