One of the most popular club planes in France is widely used by instructors in that country. Now we welcome the Sky Ranger to North American skies.
In France, as with much of Europe, many ultralights are owned by aero clubs which frequently manage recreational airfields throughout the continent. Run a little differently in each location, they provide common ways for average pilots to fly and for newcomers to be introduced to flight. Virtually all aero clubs provide instruction, often through associated flight schools. Clubs also own and maintain aircraft – lots of them. This has worked especially well with sailplanes; Europe has more than twice as many sailplanes as the United States and several times the pilot population. Ultralight enthusiasts have followed this example.
The Sky Ranger arrived in the mid-1990s at French ultralight aero clubs that dot the landscape, and has done very well. U.S. importer Sabre Aircraft says, “It’s the most popular ultralight in France, especially with the flight schools.” In more than just 6 years, the company claims deliveries of about 500 aircraft. We can explore the reasons.
Designer Phillippe Prevot (fill-LEAP pre-VOH) created very broad design goals for the Sky Ranger: “develop an airplane| [with good] performance but with the possibility of being built by two persons in a week, to be inspected and maintained by a person without special or technical knowledge.” Does that sound like a formula for success with clubs?
It also worked with flight schools. Instructors want to teach, not build, so an ultralight optimized for fast building would be a great benefit to the primary goal of flight instruction.
Flight schools and aero clubs are full of pilots with less experience. Parts will be damaged by hard landings and easy repairability is another desire of flight schools who want to teach, not repair. Clubs can handle more of their own work if the ultralights they operate are simple. The Sky Ranger qualifies.
To keep the design as simple as possible – part of the overall design goal – the Sky Ranger has no welding, uses only straight main airframe members, and has no composites for structural components. Sabre Aircraft boss Richard Helms says, “People compare the Sky Ranger to the RANS S-6 Coyote II. They say it’s a knockoff, but Phillippe didn’t take anything from the Coyote. It’s built completely differently though it does look a lot like the Coyote,” he admits.
“The Coyote is typical general aviation construction, using welded steel, mostly dope-and-fabric covering, and a style of design that is different from common ultralight construction.
“The Sky Ranger is more typical ultralight construction with tubes bolted together,” says Helms. Use of channel and gussets, all straight tubes (which are less costly than bent ones), and no weldments make the Sky Ranger more like ultralights from the 1980s than newer designs of the 1990s.
Ultralights have always been easier to build and repair than those models coming from the homebuilt movement. Ultralight enthusiasts tend to prefer hundreds (or lower) to thousands of hours of build time, and self-repair to A&P repair. The Sky Ranger accommodates that desire.
The overall airframe design is based on triangulation from the center line of the fuselage. According to Helms, the design is sufficiently unique to have earned a French patent for its fuselage structure. Helms says the award relates to the tubing airframe structure and its lack of any bent members.
One identifying quality of this unique design is that there are no conflicting aircraft components that make entry harder; in other words, you don’t need to slide behind or step over any tubes to enter the Sky Ranger. Look around; you won’t always find that in ultralight structures, especially those that don’t rely on welded steel.
Again addressing the fact that the Sky Ranger strongly resembles the S-6 Coyote II, it is actually significantly different in basic structure or else a patent wouldn’t have been issued, Helms feels. However, since patents are only good in the country issued, this legal detail may never have been tested.
One other goal of the Sky Ranger bears noting. The designer says two people can fold the wings in 20 minutes, however, I did not witness the effort required. Folding wings have become a marketing plus for many designs and the Sky Ranger has also found this.
Electric In-Flight Adjustable Prop
The Sky Ranger is a very well-equipped ultralight, especially so for its modest pricing. It comes with hydraulic brakes, flaps, in-flight trim, remote primer, and the test Sky Ranger I flew was also fitted with electric starting and an electric in-flight adjustable IvoProp propeller.
I got an interesting lesson in electric props. I don’t have a lot of experience with them in ultralights and my general aviation background brings knowledge of systems operated very differently. On several occasions where an electric prop was installed on an aircraft I was to evaluate, the powerplant was always a 66-hp Rotax 582, 74-hp Rotax 618 or 80-hp Rotax 912. Never before had I used an in-flight adjustable prop on the 50-hp Rotax 503 that our test Sky Ranger had.
Helms has also experienced the problem I found, caused when I overpitched an engine which couldn’t deliver enough power to overcome the high pitch. Helms has seen the tachometer drop quickly from 5,700-5,800 rpm to 4,800 rpm when he went too far. At that power setting and pitch angle, the Rotax 503 can’t hold the Sky Ranger aloft and you’re going in for a landing unless you discover the problem and correct soon enough. I didn’t.
Due to my inappropriate operation of the in-flight pitch adjustable prop, I bogged out the engine and had to land in a field. To its credit, the Sky Ranger handled the landing and a takeoff from a mighty bumpy field (they never look that rough from the air, do they?).
The prop had been installed without the limiters supplied by IvoProp. Helms describes the process of installing these as tedious and time-consuming. You must make a fitting, go aloft, try out the ranges, come down, remove the prop, make an adjustment, go aloft, make another adjustment, and so forth. The effort will consume the better part of an entire day. For this reason, the limiters hadn’t been fitted to this ultralight yet. Once you gain experience with a particular plane/powerplant/prop combo, the limiters are probably not necessary. Eventually, you’ll handle it mechanically and hardly without thinking. But if you will allow others to fly your plane, I recommend you install the limiter devices and save everybody some embarrassment.
An electronic switch on the instrument panel (next to ignition switches in front of the left seat) provides the adjustment. But no gauge or other marker helps identify where you are within the possible range of propeller pitch settings. I was told that my error with prop adjustment was that I got it too highly pitched and the engine can’t turn it at sufficient revolutions. Ivo can’t set it up in advance because every engine is different. That may all be true, but how is a pilot not familiar with the particular ultralight to judge appropriate use of the electric adjustable prop?
Nonetheless, my poor operation of the control says nothing about how well it works. Ivo’s electric prop does well. From one extreme to the other I saw revs drop from 6,500 rpm to barely over 4,000 rpm solely by controlling the prop. I maintained a steady altitude and made no throttle or speed adjustments, therefore isolating the effects to the prop’s pitch alone. I would encourage more use of electric props if a reliable indicator of prop position was always used, allowing the pilot to effectively limit operation. Such a gauge or dial could also help optimize prop use similar to the way a general aviation pilot sets the prop using tach and manifold pressure references.
Checking fuel quantity in the Sky Ranger is quite easy, at least so long as you’re looking at the tank in the opposite side. Owner Tony Berman had hooked the tanks up incorrectly so only the aircraft’s right tank could feed, however, since that was the side I wanted to see, this caused me no problems. If it feeds equally from both tanks this should also provide plenty of low-fuel warning to the pilot.
The Sky Ranger’s standard equipment flap lever is tucked almost out of sight between seats and has a squeeze handle to allow movement between three positions of flaps plus a neutral position. At the back of the seat frames between pilots, Prevot located the in-flight trim. A small lever adjusts tension on the elevator linkage in a manner common to ultralights.
Two large pilots can fit well in the Sky Ranger, says Helms. “I and another 200-pounder fit comfortably and the Rotax 503 performed very well,” he explains while also endorsing the lower-cost engine.
And entry is certainly simple with only a lone side member to block access. Ending up at your hips, the single tube is padded and hardly in the way. In fact, you may come to like it in flight, especially with the doors off.
I have lots of experience with even more open ultralights and I like that sensation. However, in the Sky Ranger with no doors installed and almost no side structure, I got a little weird feeling that I could fall out. This sensation heightened when I deliberately made uncoordinated turns and maneuvers to sense the ultralight. Though I rarely get this feeling and can’t explain it in the Sky Ranger, at least a very sturdy seat belt system and a short, padded tube at my outside hip offered me a little security. Doors are available for the truly uneasy.
I found good access to primary controls such as joystick, flap lever, and trim lever. But I really didn’t care for the throttle in the Sky Ranger. For me, it is too much of a reach and offered no place to rest my hand. If you keep your hand on the throttle as I often do (especially in tight formation flying for cover photos), the position caused fatigue. Helms says you can set up the throttle as a push-pull (like a Cessna) but that wouldn’t help much over the lever arrangement. You still have the reach and no support point.
Seats are only adjustable during construction though the seats tilt forward for access to fuel and the optional cargo bag. My reach to switches and knobs was fine so adjusting the seat wouldn’t help relative to the throttle.
The Sky Ranger felt a bit like the Kolb Mark III as your legs and feet had to angle toward the center of the fuselage. It was less pronounced than the Kolb, which has a pointy nose, but was still less than optimal in comfort.
I also noticed lot of heat being directed onto my left leg but generally into the foot area of the cockpit. While I could love this during a Minnesota winter, my foot broiled in Florida’s intense heat.
Locating the brake on the forward side of the joystick was as useful and effective as any similar mount and the hydraulic brakes worked with surprising power.
Prevot’s skylight design – basically the entire fuselage over the cabin – required that turns had to be rather steeply banked to see laterally. In aircraft like the Flying K Sky Raider I’d just flown before my Sky Ranger evaluation, you sit higher relative to the wing. In turns, you can look out the skylight. But in the Sky Ranger you use lateral vision before the turn. With the doors off and its large skylight, even including two windows in the fabric above the fuel tank area, the Sky Ranger offers very broad visibility.
Geared to Students
For this flight evaluation, I used an aircraft donated by owner Tony Berman. (Thanks again, Tony!) He and designer Phillipe Prevot built this Sky Ranger. Talk about your factory service! The two assembled and flew the plane in 3 16-hour days. Clear-coating, instrument fitting and attaching the cowl came later but in only 3 days, our test Sky Ranger went from crate to flight.
Despite this highly personalized attention our test bird had a mild right turn in it which caused me to use left rudder nearly all the time. I kept having to reposition my feet on the pedals to get a better purchase on it.
Helms says that by using the bungee cord attached well aft of the pilot in the tail cone, you could fix some turn tendency by sliding the bungee to the appropriate side. This has limits of course, but for reasonable adjustments, it may prove sufficient. By creating a small opening in the skin on the underside, you can reach up and manipulate the bungee which causes the firm rudder response. The bungee is attached to a mid-cone cross member and is the same location to make that turn adjustment. Because of this, access might be something you’d like periodically. Fortunately it’s easier than it sounds as the covering slips on the fuselage (also wings and elsewhere) and seams are joined by cord lashing or Velcro® closures.
Prevot always tightens up the return bungees on the rudder pedals because he believes it is better for students, explains Helms as he accounted for the rudder stiffness I noted. By making the pedals resist movement, you must work a little harder to fly the plane but students get necessary feedback while their tactile sense of control movements sharpens.
The dissimilarity of efforts – smooth, fairly light stick and stiffer rudder pedals – made harmony between stick and rudder less than perfect.
I made good quality but shallower Dutch rolls, which says a lot about overall control lightness, response, and harmony. As I tried to do them more steeply, I wallowed around the sky. Of course, my lack of experience in the model must also contribute to control sloppiness.
The Sky Ranger has sprightly if not inspiring performance. I loved that this 2-seater had a 50-hp Rotax 503 though Helms admits that he sees the logic for the 80-hp Rotax 912 installation. Naturally, that 912 would give stronger climbs but it also costs $8,500 more than the 503 and raises the weight of the Sky Ranger by 70 pounds.
Still, I can see that a modestly priced Rotax 503 can perform well in a flight school environment. Many people love the 503 and you save a lot of up front cash (though one 912 argument is that total overhaul expenses will be lower in the long run).
Climb is only in the range of 500 fpm, I’d estimate. Tony had not installed an altimeter so I couldn’t be accurate in my measurements. Contrarily, Helms and his 200-pound friend found the Sky Ranger to do well even in Helms’ hot home state of Arizona.
Perhaps individual performance categories are tops in their class, but the entire package must be a good one. A Sky Ranger has won World Championship status two times since 1996. Phillippe Zen, then a dealer for the Sky Ranger in France, won them both in his class. (Editor’s note: Zen won his class again in the recent World Microlight Championships held during the World Air Games in Spain. See “Competition Corner,” page 39 of this issue).
Helms is circumspect about this achievement. “If it wins, it must be a pretty good performing ultralight, but is it the best? Well|” Though he may be striving for honesty, the truth is that it won, twice, and that does mean something.
Cruise was fairly speedy, thanks to the effect of the electric prop. I recorded a high of 88 mph during some runs while Prevot reports that a 80-horse Rotax 912 will only go about 93 (however, it was unclear if that aircraft includes an adjustable pitch prop). Some claim higher speeds, but instrument error is always suspect in such measurements.
Stalls occurred at low speeds, into the higher 30s, again dependent on instrument accuracy. But intuitively I felt I could sense the lighter weight of the smaller engine and lighter airframe. All stalls, power-on, power-off, and accelerated resisted any tendency to fall on a wing and the nose break was mild or nonexistent. Indeed, good for students and the rest of us.
I did no spins or other edge maneuvers due to the lack of a parachute. Sabre works closely with BRS and a system installation is expected but was not on the test ultralight. However, they have been fitted as Helms referenced a deployment in South Africa in the last couple years. Info was sparse as to why the need arose or how the emergency system performed.
Oh, Give Me a Sky Ranger
If you have an interest in this ultralight you have several sources to see it. At the time of its introduction, the Sky Ranger was already represented in three distinct parts of the U.S. and by Speedwing Aircraft in Canada.
Sabre Aircraft, located in the greater Phoenix, Arizona area, has the U.S. and Mexico distribution rights; Speedwing has Canada. Acting as dealers through Sabre are Carlos Pereyra, owner of Arnet Pereyra who manufactures the amphibious Aventura and several other ultralights, and by Green Landings. Owner Kevin Green is enthusiastic about the Sky Ranger and has already reportedly sold several. Green also represents Flightstar Sportplanes.
The airframe and coverings are now manufactured by Aeros in Kiev, Ukraine, a company I visited barely a month ago. Once built by Synairgy in France, production moved to the eastern country in 1997. Aeros has won market favor in the U.S. and around the world for its attractively-priced and good flying hang gliders. They also make trike wings for Sabre and many others, so their entry to fixed-wing ultralights made in the manner of hang gliders is a logical development.
The Sky Ranger is built as an “ultra-fast build kit” with the flaps, ailerons, tail plane, vertical stabilizer, rudders, and elevator coming prebuilt and covered. The rest of the airframe is referred to as “a number of subassemblies.” In addition, the factory says, “All joints come with the bolts already in position and attachment brackets already in their places.”
Tony Berman says that covering the Sky Ranger was one of the easier jobs as the covering merely slips on and ties up, a big difference over conventional dope-and-fabric covering which then requires priming and painting. You save both time and money with the Dacron solution.
As sharp readers probably noticed, Green Landings advertises good prices on all models of Sky Rangers and has clear pricing about the cost to build it for you. Even if the task is supposedly quick and simple, it still takes 100 hours or more, making the Green Landing’s offer of interest to many time-starved pilots.
The basic Sky Ranger kit, without engine, runs just under $12,000. Add the 50-hp Rotax 503 plus mounts, exhaust, (non-electric) prop, and your choice of colors, and you’ll pay $15,500. Decide you need the 80-horse Rotax 912 plus its electric starter and you’ll spend almost $24,000.
Despite the higher price of the Rotax 912-equipped model, Helms says, “I’ve looked at it all and I’m convinced the 912 is the way to go.” He calculated purchase price, overhaul and maintenance, and fuel consumption and believes the 4-stroke engine is worth the considerable extra cost. He also acknowledges that the 60-hp HKS 700E 4-cycle engine would make a good powerplant for the same reasons.
To compare, the Rotax 503 adds about $3,500 to the airframe price, not including the effort of installation. Have Sabre install a Rotax 912 and the comparable value is around $11,000 (though they do the work of installation for this price). Have Sabre fit an HKS 700E and the add-on to the airframe will be about $9,200.
Big engine or little, the Sky Ranger makes an interesting new choice for flight schools and private owners. You might even try the European club system since the ultralight is aimed at multiple pilot use. Either way, you might find your home on the Sky Ranger.
|Empty weight||405 pounds|
|Gross weight||992 pounds|
|Wing area||152 square feet|
|Wing loading||6.2 pounds/square foot|
|Kit type||Fast-Build kit|
|Build time||100 hours1|
|Notes:||1See distributor and article for further details about the build effort.|
|Standard engine||Rotax 503|
|Power||50 hp at 6,500 rpm|
|Power loading||19.1 pounds per hp|
|Cruise speed||70-85 mph2|
|Never exceed speed||103 mph|
|Rate of climb at gross||600 fpm|
|Takeoff distance at gross||650 feet|
|Landing distance at gross||800 feet|
|Notes:||2Test Sky Ranger was equipped with an in-flight adjustable prop (see story).|
|Standard Features||Rotax 503, ASI, tach, hydraulic brakes, 3-position flaps, cabin with removable doors, remote choke, shock-absorbing gear, steerable nosewheel, choice of colors for slip-on Dacron covers with lash-up tightening (no painting required).|
|Options||Engines up to 100-hp Rotax 912S including Rotax 582, 618, and regular 912, also 60-hp HKS 700E, electric starter, 4-blade prop, additional instruments, assembly option, doors, and ballistic parachute.|
|Construction||Aluminum airframe, fiberglass fairing, presewn Dacron wing, fuselage, and tail coverings. Designed in France. Made in the Ukraine (by Aeros); distributed by U.S.-owned company (Sabre Aircraft).|
Cosmetic appearance, structural integrity, achievement of design goals, effectiveness of aerodynamics, ergonomics.
Pros – The Sky Ranger had specific design goals at outset: well-rounded performance, quick build, easy repair. Goals were reached. Very simple “ultralight like” construction: no welding, only straight main tubes, sewn Dacron covering. Aircraft well proven through years of use. More than 500 built.
Cons – Critics says it’s just a RANS S-6 Coyote II knockoff (though it is really quite different). New brand not yet established in America despite a strong following in France. Simple design has a boxy appearance from some angles. Only modest performance and handling (though it’s aimed at beginners).
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 Sky Ranger was well-equipped, with flaps, in-flight trim, hydraulic brakes, electric starting, and in-flight adjustable prop. Easy access to fuel tanks behind tilt-forward seats. Convenient primer on instrument panel. Plenty of room for extra instrumentation, GPS units, or radios.
Cons – Flaps, trim, and brakes are standard; other items on test plane were optional at additional expense. Fueling without removing tanks risks smelly spills inside cockpit; no exterior refueling point. Pull starting in this cockpit may prove difficult. No indicator for in-flight adjustable prop and no limiters installed to help prevent incorrect operation.
Instrumentation; Ergonomics of controls; Creature comforts; (items covered may be optional).
Pros – Instructor and student share a joystick but have dual pedals and a throttle for each seat. Flaps and trim between seats also very accessible. Seats tilt forward to allow access to the twin fuel tanks. Removable doors. Four-point seat belts provided as standard. Optional cargo bag aft of seat is fairly roomy.
Cons – I didn’t like the reach to the throttle and it has no hand rest to steady your movements (a Cessna-style push throttle is available). Support structure passing through panel disturbs visibility somewhat. No doors were available to examine for latch security and operation. Your legs must angle toward the pedals in a somewhat uncomfortable way.
Taxi visibility; Steering; Turn radius; Shock absorption; Stance/Stability; Braking.
Pros – Standard hydraulic brakes worked better than expected; fairly powerful slowing. Mounted on joystick, either seat has brake access. Entry is very good; no tubes block your movement in or out. Seats tilt forward to allow fuel tank and cargo bag access. Not windy to fly with door removed. Panel readability and distance are good.
Cons – Simple seats may not prove comfortable on long flights (my 1-hour flight showed no discomfort, however). Gear absorption limited to flex in large gear leg slab and air in the tires. No differential brakes to aid maneuvering. Taxi turn radius was not tight.
Qualities; Efficiency; Ease; Comparative values.
Pros – Tough main landing gear proved itself during an out-landing in a bumpy field (see story). Very good clearance assures rough-field landings won’t affect main airframe members. Good forward and lateral visibility. Modest speeds for takeoff and approach to landing permit speeds slow enough that I hardly used the flaps.
Cons – Overhead skylight was less useful in turns as you sit well below it; must be highly banked for usefulness (though still good for overhead traffic). Factory ground roll distances listed in specifications seem much longer than my experience. Designer recommends limiting crosswind operations to 17 mph.
Quality and quantity for: Coordination; Authority; Pressures; Response; and Coupling.
Pros – Center joystick is convenient to use from left seat. Plenty of movement range inside cabin due to placement. Coordination exercises went well to shallow angles (where most students fly). Adverse yaw was average among ultralights. Precision turns to headings went very well; I see no problem in crosswind operations. Controls light enough that I rarely used trim (flying solo).
Cons – Rudders were a little stiff, making harmony less than optimal. Dutch rolls couldn’t be done to steep angles successfully on first trials. No arm rest for stick or throttle; both could use one in my opinion. Test Sky Ranger had a little right turn that took constant correction (though I’m told the adjustment is an easy one).
Climb; Glide; Sink; Cruise/stall/max speeds; Endurance; Range; Maneuverability.
Pros – Light weight (especially 50-hp Rotax 503 model) helps overall performance. Three-blade prop (with four as an option) makes for smoother engine operation. Sky Ranger did very well on the 503, especially considering some have fit the 100-hp Rotax 912S. In-flight adjustable prop extended the range of operation.
Cons – Climb is somewhat uninspiring with the 503; unable to measure without an altimeter but designer lists 200 fpm (I found it much stronger even with 503 power though perhaps in-flight adjustable prop helped). Flies at ultralight trainer speeds; I liked it, but some will want more speed capability. Fuel use with 503 is reportedly higher than 912.
Stall recovery and characteristics; Dampening; Spiral stability; Adverse yaw qualities.
Pros – Very modest stall results; no breaking over and no drop on a wing. Work underway for parachute installation. Longitudinal stability appeared to be good, returning to level slowly but positively. Four-point seat belts add security. Stalls recovered quickly and without wing drop.
Cons – No doors and no side airframe members may give some concern. Steady right-hand turn made some stability observations difficult (though an adjustment sounds reasonably easy through opening in underside fabric, then sliding restraining bungee to appropriate side).
Addresses the questions: “Will a buyer get what he/she expects to buy, and did the designer/builder achieve the chosen goal?”
Pros – Very fast-build kit with substantial work done for you (flaps, ailerons, tail plane, rudder, elevators all built and covered; many bolts already in position). Representation by Sabre Aircraft is a plus; the trike-maker has been a success for many years. Modest overall prices (under $16,000 with Rotax 503).
Cons – Design has no track record or history in America and success in France is not known to American pilots. Uncertain resale values at this stage. Marketing information (option prices, more explanatory literature) still being created. Simplistic ultralight that may not appeal to sophisticated buyers.