October 2013 Issue
Just Aircraft’s SuperSTOL
Amazing STOL performance in a plane you can live with every day.
There are a number of airplanes that justly claim STOL (short takeoff and landing) performance. Such names as Super Cub, Husky, Maule and Helio Courier have earned their STOL credentials with years of hard work in the bush around the world. When someone comes along and grabs the name SuperSTOL for themselves, as if to say, "I'll see your STOL claim and raise you some more," it's only right that we call them on it and demand they put their cards on the table. That is exactly what the aviation community did to Just Aircraft at Sun 'n Fun 2013, and they came away pretty impressed.
Gary Schmitt (left) and Troy Woodland are partners in Just Aircraft. They are presently overwhelmed with orders for the new SuperSTOL.
Troy Woodland and Gary Schmitt teamed up 11 years ago to create Just Aircraft and their first plane, the Escapade. Two years later they came out with the Highlander, a plane and kit that has a pretty good claim to STOL status itself. With hundreds of completed kits now flying, it is easy to find some entertaining video of a Highlander landing and taking off in some unexpected place. Just type "Dead Stick Steve" into your favorite search engine to see some now-well-known Highlander antics. But as impressive as the Highlander is, Troy and Gary thought they could do better. "I want a plane I can take off and land in my backyard," Troy said, and that is just what they have created.
The SuperSTOL is a no-compromise short takeoff and landing machine. It employs a thicker airfoil than the Highlander and combines that with two-thirds span flaps that extend to 45°, self-actuated slats in the leading edges of the wings, and some innovative landing gear to make backyard landings a real possibility, if you have the right backyard.
Despite the fancy aerodynamics, the SuperSTOL's performance does not come solely from landing at slow speeds, although it does land at around 35 mph. Its impressive performance comes from the ability of the airplane to make a fairly steep approach, land precisely on a spot without any appreciable float or flair, and stay planted on that spot. It is the combination of aerodynamics, landing gear and brakes that comes together in a most complimentary manner to produce uncanny landing performance.
Up, Up and Away!
The bane of many STOL aircraft is the ability to get into places that they can't get back out of, but such is hardly the case with the SuperSTOL. A 3-blade Kiev ground-adjustable prop teamed with a 100-hp Rotax 912 ULS engine provide ample thrust to launch the SuperSTOL skyward, and the unique aerodynamics of the SuperSTOL wing provide plenty of lift. Takeoffs at full gross are impressive, but takeoffs when lightly loaded are simply amazing. Here's the drill: Push throttle forward, push stick forward, extend one notch of flaps, pull back on stick. As quickly as you can say that, the plane is in the air. At full gross the process is extended a bit, but ground rolls of 200 feet or less are routine.
Just Aircraft believes that a good bush plane is a light bush plane. In keeping with that philosophy they have installed a bare minimum of equipment in their panel, but nothing says that you have to do the same. There is plenty of room for whatever you might wish to include.
Climbout can be quite steep if you desire, making obstacle clearance less intimidating than it can be in many other aircraft. The plane will even climb with full flaps, although one notch of flaps makes much more sense. Circling tightly as you climb above a small field to clear trees or escape the clutches of a small alpine lake gives the SuperSTOL pilot options that others can only dream about.
The only thing that could make the SuperSTOL take off even more quickly is more power. With this in mind, some customers are already working on installing 130-hp turbocharged 912 engines in their airplanes. This engine grafts the Rotax 914 turbo system onto the larger 912 ULS engine to produce 15 more horsepower than the standard 914. It's fair to say that you will probably need a helicopter to take off shorter than a SuperSTOL equipped with such an engine.
Typical SuperSTOL landings are three-point, with a rather unceremonious thud, and a very short roll-out.
Landing on a Dime
The word impressive quickly comes to mind to describe takeoff performance in the SuperSTOL, but unnerving is probably a better word to describe the first few landings. They go something like this: Turn to final and reduce power to slow down. Put in a notch of flaps, and as the airspeed drops through 60 mph, see the leading-edge slats pop out with a soft bang. Put in the full 45° of flaps and slow to 40 mph indicated. Control sink rate with power and pick your spot to land. Just before you set down, cut the power and arrive with an unceremonious plop. As the landing gear compresses with the impact of the landing, apply the brakes and come to a quick stop. There is no flair, no dancing on the rudder pedals, and little chance of a nose-over upon applying the brakes. The plane just stops where you set it down. It feels kind of weird actually, but it works.
The aluminum-structured wings are light and large—just the ticket for landing on a spot in a backyard.
With a sink rate of 500 feet per minute or even more (there was no VSI in the test airplane), as you come in, you are just sure you are going to land too hard and bounce to the moon, but the SuperSTOL gear just sucks it up and laughs at your misplaced case of nerves. And all those warnings about using brakes on the runway? Forget about it. With the gear set well forward, you just aren't going to put this plane on its nose with braking. The biggest problem for pilots will come when they step away from a SuperSTOL and try to apply these techniques to some other airplane. In a word, don't.
This look from the front presents a great view of the SuperSTOL landing gear with its 6-inches-plus of travel and nitrogen-charged shocks. The change in wheel camber is reduced by attaching the suspension swing arms to the center of the fuselage.
Every good bush plane needs a set of real bush tires. These 29-inch Airstreaks make an important contribution to the Super STOL's land anywhere capability. They add about $3000 to the cost of the kit.
What About Those Slats?
Slats are aerodynamic devices that extend from the leading edge of a wing. They increase lift by increasing the effective chord of the wing and keep the airflow attached to the top of the wing at high angles of attack. They are found on big airliners and the odd hardcore bush plane, but are otherwise not very common. Their effectiveness is well-proven, but the weight and complexity they add are simply not justified on most light airplanes. On the SuperSTOL, they prove their worth by delivering performance unachievable by other means.
The slats are essentially invisible to the pilot, except for the dull bang when they pop out, a sound that is quickly ignored after you get used to it. There is no change in control feel associated with slat deployment. In fact, another unexpected thing about the SuperSTOL is that the slats often come out only on one side initially. You would think this would really affect the feel of the airplane, but it doesn't. Turning or uncoordinated flight will often cause one side to deploy before the other, but when the other side does deploy, there is no noticeable feedback to the control stick.
The secret to the SuperSTOL's performance is its swing-out slats. Here you can see a slat support arm and how it folds into a slot in the slat when not in use.
The SuperSTOL system is similar to the design used on the Helio Courier and has a similar beneficial effect at low airspeeds. The difference is that the Helio Courier slats slide in and out on tubes that project back into the wings, but the SuperSTOL slats swing out on short arms that fold into notches in the slats when not in use. This gives the slats a bit of sideways motion as they deploy. These swing-out slat arms are much easier to fabricate and lighter than the Helio Courier devices that served as their inspiration.
Long-travel off-road-type suspension on the mains and the tailwheel make steep approaches to firm, short landings much easier. Note that there are no steering cables going to the tailwheel.
The traits that make the SuperSTOL a super performer also make it unique to fly. Some serious transition training should be high on the to-do list of any pilot when taking on the SuperSTOL for the first time. Differences begin with the lack of a steerable tailwheel. A tailwheel lock is an option (not installed on the test plane) for SuperSTOL builders, but steering cables connecting the tailwheel to the rudder pedals are not. You steer with differential braking. Can you actually land a taildragger that way? Well, yes, but it isn't a Cub. You need to use a different approach.
The long-stroke landing gear is just one reason this airplane stays where you land it. This almost-complete aircraft seems to be begging for its wheels.
The most unconventional aspect of the SuperSTOL may be its landing gear. It is more reminiscent of a serious off-road vehicle than an airplane. In fact, its nitrogen-charged shock absorbers are made by Fox, a company well-known to off roaders and motorcycle racers. The long-travel suspension on the maingear and the tailwheel make those drop-in landings possible. The six inches plus of suspension travel and the carefully tuned dampening of the shocks allow for landings that bungee-cord landing gear could never handle. This gear system has its downside in that it adds considerable weight, but sometimes you just have to pay to play. If you are truly serious about this kind of performance, you simply have to absorb the cost that comes with it. Just Aircraft is working to reduce the weight of this gear, but it will never be as light as more conventional fixed gear.
The Rotax engine may be seen as unconventional to many, but with the number of Rotax-powered amateur-built airplanes now exceeding the number of Continental-powered Experimentals, it is perhaps time to redefine conventional to include this most-successful powerplant. It is different from the more traditional Lycoming and Continental engines in that it is a geared engine, turning at upwards of 6000 rpm. Your idea of proper power settings will need to be recalibrated if your flying experience is behind slower-turning engines. Rotax maintenance routines also differ considerably from what most people consider standard, so prudence demands some specialized training if a Rotax engine is in your immediate future.
The flap track mechanism looks complex but it works quite well, allowing for full 45° flap extension with minimal effort.
Cruising in the SuperSTOL
There are times when you are not taking off or landing the SuperSTOL. In fact, that will be most of the time. Fortunately, cruise flight is pretty conventional. Control pressures are light and well-coordinated, and the airplane is amazingly stable, making hands-free flight much easier than it is in many other rag-and-tube airplanes. Turns work best with a little bit of leading rudder at the beginning of the turn, but nothing in that regard is particularly unusual or of any great concern. Taildragger pilots should expect to use the rudder pedals from time to time.
There was no turbulence encountered during the test flight, so it's hard to offer an opinion on how it might handle bumpy air, but in general, light sport-type airplanes do get pitched around more in unstable air than heavier airplanes. It is worth noting, however, that the SuperSTOL has less wing area and thus a higher wing loading than a J-3 Cub. Higher wing loading, combined with the SuperSTOL's better stability, should allow it to ride out turbulence with less drama than a Cub.
Visibility out the sides is outstanding with the SuperSTOL's all-glass doors, but it does cruise at a slightly nose-up attitude. Woodland says that the angle of incidence of the horizontal stabilizer may need a little adjustment to correct this. Cabin room is very ample, especially for a light sport airplane—lots of legroom and shoulder room, even for big guys. The baggage area is bordering on cavernous. With the empty center of gravity at the forward limit, it is hard to put too much weight in the back, except of course, when you run up against the 1320-pound gross weight required for Light Sport compliance. With the non-LSA allowable 1550-pound gross weight, you can pile gear into the back till your heart's content.
Cruise speed with the big, 29-inch Airstreak tires is around 90 mph. With smaller tires and the prop reset for cruise pitch, a cruise speed of 105 mph or so should be possible.
Just Aircraft installs vortex generators to the underside of the horizontal stabilizer for greater elevator authority at low speeds.
ELSA vs. Experimental Amateur-Built
Just Aircraft does expect to eventually go through the process of making an ELSA option available for builders, but there is no present commitment from them on when that might come. ELSA would allow builders to avoid the hassle of majority amateur-built compliance (the so-called 51% rule), and it would allow non-builder owners to acquire a repairman's certificate. However, it would greatly reduce the flexibility of the building process. Most builders think that Experimental/Amateur-Built status is the way to go, and Just Aircraft agrees, but they are still interested in addressing the wishes of ELSA builders at some future date.
The Bottom Line
The SuperSTOL is a great plane with eye-popping STOL performance. That much is beyond dispute. But how many people need that performance, considering its extra cost and added weight? You can buy a lot of gas with the nearly $14,000 added cost for a SuperSTOL versus a standard Highlander. But for those who want that extra edge in performance and the safety that comes from being able to land just about anywhere, the SuperSTOL may be a real bargain. With either plane, operating costs should be low and reliability fairly high, making the value calculation tougher than it might first appear given the SuperSTOL's performance. But if you just love the idea of being able to land on the numbers and exit the runway at the point where most people enter it, this may be just the plane for you.
For more information call 864-718-0320 or visit www.justaircraft.com.
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