One of the all-time successes in the world of kit-built light aircraft is the Kitfox. Challenged in terms of success by Vans Aircraft’s RV series, many Kitfox aircraft have been sold. Denney Aerocraft, the original manufacturer of the Kitfox design, never considered a single-place machine. Why would they? Even pumping out 60 planes a month in their heyday of the early 1990s, they were barely keeping up production quotas.
Avid Aircraft, producer of the Avid Flyer (the forerunner of the Kitfox) also never pursued a single-place model. In the early 1990s Avid was also going strong. But by early 2000, things looked a bit different.
Dan Denney sold Denney Aerocraft to Phil Reid in the early 1990s, and the company was renamed SkyStar Aircraft. The company was then sold again to Ed Downs and partners, with the company name remaining SkyStar Aircraft. By this time, the Kitfox design became somewhat saturated, and other creations muscled into the limelight of pilot attention. Translation: SkyStar needed to enlarge their product line to keep things moving at the Idaho factory.
Out came the Kitfox Lite, a single-place Part 103-compliant ultralight. SkyStar did an excellent job on the Lite. The company hasn’t lost their touch and their show aircraft are finished in a very professional way. However, they were already a little late to the party.
Before the Kitfox Lite came the Sky Raider from brothers Ken and Stace Schrader and their company, Flying K Enterprises. Both Schraders had been employed by Avid Aircraft and Denney Aerocraft. Each worked in various departments, learning the Kitfox/Avid trade along the way.
When they branched out on their own, the original Kitfox design was etched into their minds. It should be no surprise that their Sky Raider ultralight looked and flew much like the now-legendary Kitfox design. However, they marched to their own drummer, starting with a single-seater and hoping to find a ready market.
They did. Sky Raider deliveries were steady and Flying K even built fuselages for SkyStar’s Kitfox Lite. (Contrary to what many believe, the market for single-seaters remains somewhere between 30-40% of the total ultralight market.)
Call it the Dean Wilson phenomenon that an aircraft’s original “look” doesn’t disappear even when “edited” by several other designers. Wilson gave birth to the original “Kitfox look” with his Avid Flyer design, and that “look” was first produced by Avid Aircraft where Dan Denney had been employed in a sales capacity. Wilson was a restless designer who was always looking ahead. Wilson and his company seemed more interested in innovation than production. Dan Denney saw an opportunity and took it, branching off to form his own company.
Denney changed the design slightly to meet his perception of market interest and proceeded to market Denney Aerocraft vigorously. The rest is history. Denney Aerocraft’s Kitfox went on to a spectacular run, while Avid Aircraft began a slow fade to black that has only recently changed to better news.
During this war of giants Denney Aerocraft and Avid Aircraft, the brothers Schrader kept at their jobs, learning continuously and watching the lessons of each company. When they came out with their Sky Raider, it was good and Flying K immediately garnered a number of orders.
Somewhere after this point the story gets even more complicated. And personal. And far beyond the scope of an ultralight pilot report.
Not long after incorporating, the brothers split up. Ken Schrader continued with Flying K Enterprises, producer of the Sky Raider. Stace parted and ultimately formed Rocky Mountain Wings. Sadly, Ken lost his life in an aircraft accident only months later (see “Flightlines,” April 2000 Ultralight Flying!). Flying K has soldiered on but Rocky Mountain Wings now also has arrived on the scene.
So, after years with no single-place plane with that “Kitfox look,” you now have three choices: SkyStar Aircraft’s Kitfox Lite, Flying K Enterprises’ Sky Raider, and Rocky Mountain Wings’ Ridge Runner. All use the same fuselage. If you want a 2-seat version, SkyStar has their Kitfox Light2, a side-by-side 2-seater downsized from the original Kitfox design.
And now, both Flying K and Rocky Mountain Wings have 2-seaters… well, let’s call them “part-time 2-seaters” or “one-and-a-half seaters.”
Now a “2-Seater”
Though it was the lack of a single-place design which lead to a market opportunity for the Schrader brothers, both Flying K’s Sky Raider and Rocky Mountain Wings’ Ridge Runner are now available as 2-seaters. However, they’re quite different than the older Kitfox designs, as all SkyStar 2-seat designs feature side-by-side seating. In each case, the Sky Raider II and the Ridge Runner Model II use what I’d call a tight tandem configuration that stuffs two people into a space where one would fit comfortably.
Yet given a common buyer’s request to have an extra seat for the occasional passenger, the Ridge Runner Model II is a market-answering design. Since non-trainer 2-seaters are often flown with only one on board, the aft seat configuration makes sense.
The New Kolb Aircraft Company offers two designs with the same idea. Their FireStar II and SlingShot II each offer a rear seat for smaller passengers. And all these 3-axis machines are following the lead of trikes which have long packed two people into a small tandem space. Top trike maker Air Cr|ation even offers a special model that has been favored by the market. Their Buggy is truly a single-seater that can do duty as a 2-seater if needed.
At the heart of the Ridge Runner nonetheless remains a single-seat version of the Kitfox, and fortunately it remains a lively and fun machine to fly.
The Model II version of Rocky Mountain Wings’ Ridge Runner uses dual 5-gallon tanks, one located in each wing. The Part-103 model uses only one of these, however, the 2-seater needs the extra gas to feed the 50-hp Rotax 503 DC that replaces either the 25-hp Hirth F-33 or the 40-hp Rotax 447 on the single-seater. Builders can make a see-through indicator for fuel quantity visible through the inboard wing root on the Model II. Stace advises that if you lift the tail, fill with 1 gallon, mark a line, add a second gallon, make another mark and so on, you’ll get an accurate indicator. Those who want to check fuel before takeoff could do another set of marks while the Ridge Runner sits on its tail.
Schrader equipped our test Ridge Runner quite well for a modestly priced ultralight, featuring in-flight trim, electric starting, a remote primer on the panel, flaps operated by a lever at your left thigh, plus differential heel brakes.
The trim knob is located just below the throttle on your left. Moving the lever forward is similar to moving the stick forward, quite intuitive. My checkout pilot, Grant Smith, told me the movement was sensitive and worked well; I agree. The Ridge Runner had no choke but had a primer located on the left of the panel near the starter switch.
Though the Ridge Runner is not a tall aircraft, fuel tank fillers located on the top of the wing could frustrate shorter pilots. Fortunately, it was very convenient and straightforward to stand up on the (optional) broad tire to handle this effort.
At the end of my flight, I noticed that the left tank oozed some fuel along that side of the aircraft. Some even crossed over the fuselage and ended up on the horizontal stabilizer’s right half. This may have been related to poor draw from the tank. An airline driver in his day job, Smith said that the Ridge Runner’s tanks are like a Cessna’s. They should drain evenly from both fuel sources.
Built for One; Holds Two
Like the New Kolb aircraft and many trikes, the tandem seats in the Ridge Runner Model II are located closely together. Make that very close.
The Ridge Runner’s seating system is interesting. What looks like one seat with a particularly long seat cushion is made into two seats. The front seat uses a strap support system which allows someone to squeeze in behind. They then use the seat back and the rear portion of the long seat cushion while the pilot has the strap set up for his seat back. In hot Florida the strap system did provide some extra ventilation.
However, the innovative seats of the Ridge Runner didn’t do much for me. Those straps for the seatback don’t offer any lumbar support and in less than a half hour, my left leg got a little numb and needed to be moved. Though long Ð and therefore supportive of your leg near the knee Ð the seat bottom is not wide, allowing someone to fit in the rear and still have a place to put their legs. Perhaps this narrowness was the reason why my rear end wasn’t fond of the seat.
Though I didn’t find the seat back straps too comfortable, perhaps I didn’t try hard enough. The strap arrangement does allow fore and aft adjustment. But despite the flexible nature of the system, it will take a rather small person to use the rear “seat.”
Unlike its sibling competitor, the Sky Raider II, the Ridge Runner has no provision for a hat rack compartment. A metal bulkhead just aft of the seat precludes creating one.
One of the photos accompanying this article shows two men inside the Ridge Runner Model II. In the rear is Grant Smith at 5 foot 9 and 200 pounds. In the front, looking no more comfortable, is Steve Troyer at 6 foot 2 and 230 pounds. I doubt Steve had sufficient control room to successfully fly the machine. Once around the patch? At most! The Ridge Runner Model II is better when at least one occupant is small.
Flown solo, with plenty of elbow and legroom, I could twist enough to find a wonderful view out the rear window. I was able to check the elevator trim before takeoff, a feature I always appreciate.
The Ridge Runner’s steering is accurate but tight maneuvering on a crowded ramp will take some planning. Fortunately, brakes are differential so they can be used to help. Stace’s ultralight uses a Matco tailwheel, which didn’t fully swivel though you could fit such a wheel if your home airport demands it.
The Ridge Runner’s heel brakes are like those on the Sky Raider II but they seem easier to operate, perhaps because the wood floor lets your foot find the small pedal easier than when your heel rubs on floor carpeting.
Good Taildragger Landings
Smith advised me that 50 mph was about right on approach, that 60 mph was overkill, and 40 mph will cause you to plop in on the gear. I explored all speeds mentioned and as with his other pieces of advice, he was precisely right.
The Ridge Runner flaps operate by a lever tucked down beside your left thigh. A push-button handle makes adjustments something you can do by feel, a very good feature on short final when your concentration shouldn’t be disturbed. One way to tell the Ridge Runner (and Sky Raider) apart from the original Kitfox is that the older aircraft uses flaperons while the Ridge Runner has slotted flaps. They proved sufficient enough for approach path control that I only experimented with slips on a couple of landings.
My focus as I approached for my customary series of landings was on the potential for ground loops. The rudder pedals had a quick response and it seemed to me that too much pedal could get the tail on the wrong side of the nose. Yet every landing I made went much better than anticipated.
You may be wondering about my consistency, as I wrote earlier that the Ridge Runner doesn’t turn too tightly yet ground loops were on my mind. The explanation is that pedal response is good but the tailwheel didn’t deflect far. It turned readily, just not quickly.
Contrarily, takeoff seemed to require more concentration. A combination of P-factor and torque from the wide Powerfin prop coupled to the aircraft’s 50 horsepower caused me to creep off to the right on the first couple of launches. A little left rudder corrected the problem but took my attention.
The ailerons weren’t as fast as I’d been expecting when I recalled the zippy nature of the original Kitfox design. However, they sure offered enough snap to allow reasonable crosswind operations.
Roll rate was dampened enough for newer pilots to feel more comfortable yet the pressures are light and easy, so you don’t get a Nautilus workout. Grant says he timed a 3-second 45-to-45 reversal and I found this accurate in my own checks.
Nonetheless, I didn’t keep the ball centered at all times. In truth, I had no turn and bank coordinator ball but I could feel asymmetric breezes coming through the side windows so I know I wasn’t always flying exactly straight. Better technique develops over time but I’ve wired into some other ultralights faster.
Grant Smith indicates that Rocky Mountain Wings offers a Cub-type rounded, elliptical tip which he believes might make the ultralight handle a little nicer. That shape would also conform with the rudder and elevator better than the squared tip I flew.
Performance for Non-Beginners
In my opinion, the Ridge Runner represents a move-up ultralight. The taildragger design may put off those with only tricycle experience. I found it easy to land but I have a lot of taildragging time.
Rocky Mountain Wings’ aircraft is also a performance-oriented design in the ultralight class. Stall came in about where the factory indicated in the low 30s. Climb is very strong with the 50-horse Rotax 503 DC. The factory says 1,600 fpm and she did go heavenward like an angel. But again, my experience was in the STOL wing version. The “Speed Wing” variation would surely trade some climb for higher cruise. The slower flying wing never let me see an 80-mph cruise.
Joining the potent Rotax 503 dual carb to the wide blade Powerfin prop makes a substantial powerplant for the lightweight Ridge Runner (only 350 pounds empty). Even at the tip, the Powerfin is still 3 inches wide and this increasingly popular prop evidently pumps out the thrust.
The Ridge Runner exhibited significant adverse yaw. Perhaps the Runner’s quick aileron response accounts for some of this characteristic.
The Ridge Runner showed adequate longitudinal stability although it was rather slow to return to level. Pitch pressures were light. Some aircraft return to level with authority but any return to level shows dynamic stability. Once again, I felt this is an ultralight for someone with a few hours of good experience in his or her logbook.
Since the Ridge Runner is like its progenitor, the Kitfox, keeping the ball centered can be challenging while you’re first gaining experience with it. I’d always like a yaw string for this kind of test-flying. It is the most elemental of coordination “instruments” and it never lies (nor needs batteries). Six inches of yarn and a small piece of duct tape may help you get used to your own Ridge Runner.
On one downwind leg with my feet on the floor trying to rest my left leg (due to the narrow seat, I believe), I found the Ridge Runner didn’t want to fly straight. I had a slight breeze which pushed me the way I was wandering, but my airborne notes reflect that it wasn’t so much a turn as a lack of wanting to fly straight without input. Indeed, Stace told me later that after last-minute changes to the model before going to the airshows, he had not fully dialed in the control cable rigging.
Rocky Mountain (Wings) High
Though it may seem like it, the Ridge Runner and the Sky Raider II aren’t identical. The difference may seem subtle, but is real and can affect how some pilots react to the ultralight.
The Ridge Runner came to the market after the Sky Raider with a few changes made to the tail. According to Stace, engineers increased the horizontal stabilizer and the elevator, adding a couple inches of chord. He wouldn’t disclose all the secrets, but said the newer design brings the tail up more readily than the slightly older Sky Raider design.
You may also choose from two wing selections Ð an unusual choice on any aircraft brand. The Ridge Runner I flew had the original STOL (Short Takeoff and Landing) wing. Now you can also select their Speed Wing, featuring a new airfoil, debuted at airshows this year.
The new wing is easily 5-6 mph faster, says Schrader, which explains why I was unable to see cruise speeds as fast as new brochures list.
Since flying their first Ridge Runner in October 1999, barely 2 years ago, Rocky Mountain Wings has taken orders for better than 70 aircraft, and has delivered more than 50 kits. The Ridge Runner first flew with the new wing in April 2000 and more than a dozen of these are already logging hours.
For those uncomfortable with the idea of building a dope and fabric aircraft, Stace offers a Builder’s Assistance Center. Rocky Mountain Wings provides space to do your own work, and factory experts are available to help you through the harder parts or to guide those new to the effort.
Given Stace and his staff’s down-home Idaho ways, I can imagine that building your own Ridge Runner under their gentle supervision would be an experience you’d never forget. What a great vacation. And you could fly home when you’re done!
|Seating||2, tandem *|
|Empty weight||350 pounds|
|Gross weight||950 pounds|
|Wing area||99.4 square feet **|
|Canopy Loading||9.6 pounds per square foot ***|
|Build time||200-400 hours|
|Notes:||* seating is really 1 + 1, not true 2-place
** optional wingtips increase area to 109 square feet
*** assumes you can load the plane to max gross
|Standard engine||Rotax 503, dual carb|
|Power||50 hp at 6,500 rpm|
|Power loading||18.3 pounds per hp|
|Cruise speed||75 mph|
|Never exceed speed||110 mph|
|Rate of climb at gross||1,600 fpm|
|Takeoff distance at gross||100 feet|
|Landing distance at gross||125 feet|
|Standard Features||Prewelded chromoly steel airframe, all hardware from firewall back, Rotax engine mount, heel brakes, engine cowling, in-wing tank, fabric, glue, seat belt and shoulder harness, left-side door, windows for both sides, chromoly jury struts.|
|Options||Welded steel powder coating, quick-build wings (can include wings set to fuselage), quick-build kit (cuts time to 150-300 hours, says factory), fully-assembled option, auxiliary fuel tank, extended bungee gear suspension, wheel penetrating skis, push button flap handle, speed or STOL wing choice.|
|Construction||Welded 4130 steel tubing airframe, wood wing components, fabric and painted exterior. U.S. owned and operated company.|
Cosmetic appearance, structural integrity, achievement of design goals, effectiveness of aerodynamics, ergonomics.
Pros – Resemblance to Kitfox, Avid Flyer and Sky Raider is deliberate and honest; principal Stace Schrader worked at all companies prior. Proven design shape; Kitfox sold thousands. As perhaps the third generation, the Ridge Runner retains all the good old qualities and adds ones buyers have requested in the interim.
Cons – Not unique, given its close resemblance to other models especially SkyStar’s Kitfox Lite. However well executed, this design shape is getting somewhat dated (though it continues to work well). Pilots without taildragger experience may want to steer clear.
Subsystems available to pilot such as: Flaps; Fuel sources; Electric start; In-air restart; Brakes; Engine controls; Navigations; Radio; (items covered may be optional).
Pros – Test plane equipped with trim, electric start, remote primer knob, flaps, differential brakes. “Conventional” tractor engine configuration is popular with some buyers. Repair access is good. Panel is large enough for more instruments. Basically a simple plane with numerous features.
Cons – Standard features on the Model II will dictate N-numbers; the single-seat version qualifies for Part 103 but can’t have the large engine, electric start, and so on. Fueling is atop wing, and optional large tires give a convenient lift to shorter pilots. Must remove cowl to work on engine.
Instrumentation; Ergonomics of controls; Creature comforts; (items covered may be optional).
Pros – Skylight design illuminates interior and helps visibility in steeper turns. Adequate room for more gauges or a radio. Simple entry to the front seat. Solo seating has a long leg support (though not very wide). Four-point seat belts were appreciated. Interior of cabin nicely achieved. Controls easily reached.
Cons – Entry to the rear seat is challenging (except for very small people). Seat cushion is narrow to accommodate person in back. No quick seat adjustment. No cargo or hat rack area. Door design didn’t latch particularly well.
Taxi visibility; Steering; Turn radius; Shock absorption; Stance/Stability; Braking.
Pros – Differential brakes help close-quarter steering (though still can’t maneuver tightly). Heel brakes with a smooth floor (not carpeting) made sliding my heels for brake action more intuitive. Skylight facilitates pre-takeoff traffic scan. Large tires and bungee suspension smoothed the bumps.
Cons – Tailwheel did not fully swivel so turns tended to be wide (differential brakes help). Brake effectiveness was modest. Rudder pedals get a lot of action for the input, meaning poor taildragger technique could invite a ground loop. View over nose means you’ll need to lean left and right.
Qualities; Efficiency; Ease; Comparative values.
Pros – Tailwheel did not fully swivel so turns tended to be wide (differential brakes help). Brake effectiveness was modest. Rudder pedals get a lot of action for the input, meaning poor taildragger technique could invite a ground loop. View over nose means you’ll need to lean left and right.
Cons – Takeoffs took more concentration than expected; 50-horse Rotax 503 DC and wide 3-blade Powerfin prop provided lots of thrust, enough to pull you off to the right. Though its tendencies aren’t bad, the Ridge Runner is a taildragger and you can’t forget that.
Quality and quantity for: Coordination; Authority; Pressures; Response; and Coupling.
Pros – Aileron and rudder response are very good. Harmony was also quite good. Controls are light to the touch and easily reached. Overall a very good package in the handling department. Dutch roll exercise went well right from start. Flaps operated easily and intuitively.
Cons – Roll rate may prove too quick for some buyers, at least without more experience (though it’s not unreasonable at about 3 seconds, 45-to-45). I recalled the challenge of keeping the ball centered in a Kitfox; the Ridge Runner shares some of that (though no ball was installed).
Climb; Glide; Sink; Cruise/stall/max speeds; Endurance; Range; Maneuverability.
Pros – Plenty of power with a high-efficiency prop gave the Ridge Runner a vigorous climb (factory lists 1,600 fpm). Good sink rate performance despite small wing area (only 100 square feet). A well-loaded Ridge Runner Model II can cruise 80 mph, says factory; I found slightly less flying with STOL wing.
Cons – With the Rotax 503 DC and a passenger, you can expect high enough fuel use to warrant the optional fuel tank; on standard tank, range will be quite limited. Open windows probably kept me from seeing higher cruise speeds but I wouldn’t want the windows on in hot weather.
Stall recovery and characteristics; Dampening; Spiral stability; Adverse yaw qualities.
Pros – Stalls broke clearly but predictably. Plenty of stick range through all maneuvers attempted. Power response was positive, that is, nose up on power up and vice versa.
Cons – Adverse yaw was definitely present. The Ridge Runner needed some rudder input to fly straight (possibly a linkage adjustment was needed?). Longitudinal stability was on the slow side in recovery.
Addresses the questions: “Will a buyer get what he/she expects to buy, and did the designer/builder achieve the chosen goal?”
Pros – Rocky Mountain Wings’ Ridge Runner Model II is only $400 more than their single-seat model before engine and paint cost. You could get airborne for about $12,000 to $13,000. Though tight, the Model II does address desire for a second seat. Company offers a Part 103-compliant single-seater. Airshow aircraft was nicely done, painted interior matched exterior.
Cons – Fly a Model II and you’ll need to N-number and get an FAA pilot’s certificate. Building a Part 103-compliant single-seat Ridge Runner will require giving up some options and using a small engine.