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Denny Kitfox

Skystar Kitfox

 

The Kitfox Model 1 introduced the “bump” cowl that has become the signature of the Kitfox.  This cowl design was originally intended to accommodate a small radial engine, but the engine intended for the Kitfox never matured.  The “round engine” look was retained, and remained popular.  The Model 1 had an empty weight of only 425 pounds, and a gross weight of 850 pounds.  The Rotax 532 was the engine of choice, although other two-stroke engines have been used. From a flying standpoint, the Kitfox Model 1 is an ultralight by today’s standards.  It is a very simple, basic airplane that is light weight and relatively high powered (usually 65 hp).  The interior can best be described as “cozy,” and the aircraft was usually built without dual brakes.  The Model 1 accelerates rapidly and has light ailerons.  There is a good deal of adverse yaw coupled with a neutral yaw axis.  The adverse yaw is easily taken care of with rudder.  The wing construction of tubular aluminium spars and wooden ribs, with full span Junkers-type flaperons. The flaperons may be moved as flaps to affect pitch trim and lower the stall speed. The flaps can be extended 0-20 degrees and still allow full aileron travel.

Lowering the flaperons to more than 2/3 of their full travel will result in up to a 50% reduction in roll rate.   Takeoffs and landings are quite normal for a tailwheel airplane and easier than most.  The nose fuel tank keeps most of the mass (center of gravity) right along the centerline, and directional control is not a major challenge.

The larger, wider Kitfox Model 2 was introduced in 1989.  This “beefier” Kitfox allowed for greater useful loads and more room in the cabin.  The Model 2 featured a larger vertical tail area and the new Rotax 582 engine option.  The gross weight was increased to 950 pounds.  The airfoil and control systems remained the same as the Model 1, but spars were strengthened to accommodate the higher gross weight.  Flying-wise, the Kitfox Model 2 is quite similar to the Model 1.  The larger tail surface helped some with the yaw issues, but was somewhat offset by larger engines and the introduction of wing tanks.  Like the Model 1, the Model 2 is yaw neutral and needs to have the nose “placed” where it needs to be.  Flaperon use and characteristics are virtually identical to the Model 1.  Dual brakes were available for late Model 2 airplanes, and many earlier Model 2 airplanes have had dual brakes installed.  Ground handling is similar to the Model 1, but the increase in gross weight, therefore greater mass, does cause one to pay a bit more attention to the landing rollout.

Composite floats were developed, adding 70 lb to the airframe after substituting for the main gear.

The Kitfox Model 3 featured structural changes that were designed to improve flight characteristics and provide a better platform for more powerful engines like the new 80 hp Rotax 912.  A larger vertical stabilizer and rudder were added, as well as larger, stronger lift struts and spar carry through tubes in the fuselage.  The gross weight was increased to 1050 pounds, but the empty weight only went up by a few pounds.  This was the last Kitfox to use the original airfoil and flight control system introduced on the Model 1.

The Model 3 was the first major attempt to aggressively deal with the yaw control issue.  It should be remembered that we are not talking about yaw instability, but a neutral yaw condition.  In other words, it was desired to have the airplane return to straight flight after pressing a rudder without having to move it back with your feet.  Much of this objective was achieved by increasing the size of the vertical fin.  The flaperon system is identical to the Model 1 and Model 2, with very similar handling characteristics.  Again, the higher gross weight requires one to practice at least average tailwheel skills.

Introduced at Oshkosh in 1991, the Kitfox Model 4 was a completely new aircraft featuring innovations that enhanced the STOL abilities, improved flight handling and stability, and increased top speed by 10 to 15%.  The Model 4 featured a new higher speed, laminar flow airfoil, new flaperon design, metal flaperon attach brackets, and a brand new 2:1 differential aileron control system that allows much improved control at full flaps.  The gross weight of the Kitfox Model 4-1050 was the same as the Model 3, 1,050 pounds.

 

The Model 4 is an ideal platform for the Rotax 912 series of engines but is equally suitable for two-stroke engines. From a flying standpoint, the Kitfox Model 4-1050 was a genuine attempt to make the Kitfox handle like a contemporary, certified airplane, without losing the heritage of agility.  It worked.  The new airfoil added speed and performance.  The flaperon airfoil, area, placement and movement ratios were changed significantly.  For the first time, the flaperon moving up traveled twice as far as the flaperon moving down.  This is similar to a Piper Cherokee.  Rudder coordination was made much easier.  The flaperons continued to be used for climb and cruise pitch trim, and back pressure is required to maintain approach speed.  While reduction of roll rate was not as pronounced, the use of full flaperons did reduce the roll by up to 30% and increased the stick loads.  The vertical fin area remained the same as the Model 3, once again a bit small for the larger engines now being installed.  While yaw stability was no longer neutral, it was not aggressively positive.  It would take one more iteration to get yaw stability to a more contemporary feel.

The Kitfox Model 4-1200, marketed under the name of the Kitfox Classic 4, is the final evolution of the original Denney Aerocraft Kitfox design that began in 1984.  One of the most successful kits on the market today, the Classic 4 kit has been sold continuously since late 1991.  The Classic 4 has heavier lift struts and gear legs, as well as beefed up carry through tubes in the fuselage, to allow for a higher gross weight than the earlier Model 4 kits.  The height of the vertical stabilizer and rudder was increased by 10 inches, and the rudder depth was increased by 2 inches to allow for improved handling.  The Classic 4 is also available in a short wing Speedster configuration for those wishing more speed and a higher roll rate.

In 1994, a light weight version of the Classic 4 was introduced with a Rotax 503 as the standard power plant.  This airplane, known as the Kitfox XL, qualified as an ultralight trainer, but did not gain market popularity.  In 2001, an upgraded version of the Kitfox XL was introduced as the Kitfox Lite Squared and met with instantaneous market success.  The Kitfox Classic 4 remains suitable for both the two-stroke and four-stroke Rotax 912 engine series.  Many other engines have been adapted to the Kitfox Classic 4.

Not only is the Kitfox Model 4 (Classic 4, Speedster, Lite Squared) the final evolution of the original Denney Aerocraft concept in terms of structure and engineering, but it is the best flying of all the previous versions.  The vertical surfaces were increased significantly, resulting in excellent, positive, yaw stability.  The Speedster version of the Model 4 added aerodynamic enhancements to the empennage, including an electric trim tab.  Speedster modifications can be used on any Model 4 variant.  Handling is smooth and crisp.  While rudder coordination is needed, it is much closer to what most pilots encounter in today’s modern training airplanes.

The higher gross weight and larger wing fuel tanks cause one to pay attention on landing rollout, but the much larger vertical tail surface gives you all the control power needed, and then some.  The available electric pitch trim allows the Model 4 (in all its variations) to be trimmed for hands off flight in almost all normally anticipated flight attitudes.  Many Model 4 aircraft were equipped with the 4-cylinder, 4-stroke, Rotax 912 that produces 80 HP.  Model 4 variants are now turning up with the 100 HP Rotax 912S, resulting in power loadings that are better than the original, light weight, Model 1.  Be prepared for an airplane that is ready to fly before you are.  In 2001, the Classic 4 was packaged as the Lite Squared and introduced into the ultra light community as a two place, ultra light trainer.  This packaging resulted in the Classic 4/Lite Squared being adapted to tri-gear in addition to the familiar tail wheel configuration.

The Kitfox IV features a laminar-flow wing aerofoil as well as a new flaperon aerofoil providing a full-span, high performance fowler flap-like performance. The new wing contributes to an increase in cruise speed of around 25 mph claims the manufacturer while decreasing the stall by about 2 mph.

Computer marketing pioneer Phil Reed bought rights to the Kitfox line, changed the company name to SkyStar, brought out new sleeker looking models including trigears, and sold the company when sales began to slacken. Several groups of investors made Kitfox kits for a while, but the project eventually collapsed into bankruptcy. The McBeans have put the Kitfox, or at least one top-end model, back in the game.

In 1994, SkyStar aircraft was faced with an increasing demand to produce a significantly larger version of the Kitfox that would be able to utilize contemporary certified engines (Continental and Lycoming) in addition to the Rotax 912 engines.  The answerer to this demand was the entirely new Kitfox Series 5.  While appearing very similar to the Kitfox Classic 4, it is, in fact, a completely new design.  The Kitfox Series 5 introduced a new marketing approach in which different variations of the Series 5 were given names.  The tailwheel version became known as the Safari, and the tri-gear version (the first production tri-gear airplane based on the Kitfox design) was named the Vixen.  The Vixen utilized a swept tail, a cosmetic change that did not affect performance.

Originally introduced with a gross weight of 1400 pounds, the gross weight was increased to 1550 pounds in mid-1995.  The handling characteristics became much more like those of contemporary certified aircraft, but lost none of the agility that had become a Kitfox trademark.  As with all Kitfox aircraft, the folding wing feature was retained.  In 1998, the name of the Safari was changed to the Outback, and the Vixen became the Voyager, but the basic features remained the same.  A short wing version of the Series 5 was also sold, and it was known as the Series 5 Speedster.  Although heavier and larger, the Series 5 is an aerodynamically cleaner design than the Classic 4 and cruises at a higher speed.

The Series 5, and variations thereof, are a delight to fly.  Refinements to the vertical tail surfaces and a new, trimable, horizontal stabilizer enhanced the pitch feel.  The Series 5 has a “smoother” feel than the quick reacting Model 4, but retains the overall agility.  Yaw stability is positive and good.  The greater weight of the 1550 pound airplanes, coupled with the greater mass of Continental and Lycoming engines, causes the Series 5 to feel very much like a larger, heavier, certified airplane.  This is not a surprise, as the Series 5, along with its tooling, was specifically designed to meet Primary Aircraft certifications standards.  The tri-gear version of the Series 5 (Vixen/Voyager) is a contemporary nose gear airplane in all respects.  The use of differential braking to steer the tri-gear airplane may take some practice, but offers unparalleled ground maneuverability.  The larger engine choices result in a larger cowling and limited forward visibility during ground operation of the tailwheel version of the Series 5.  Good tailwheel proficiency is suggested before your first flight of the “limited view” Series 5.  Cruise flight in the Series 5 is nose low, resulting in very good in-flight visibility.

 

In 1990 the first Skyfox (RPX-44), the Philippine version of Kitfox, assembled by the Philippine Aircraft Company, Inc. (PACI) in agreement with Denney Aerocraft of the U.S.A., flew. By 1995 the Kitfox was being built under licence in the Philippines by PACI. The Speedster version is based on the Classic IV or series V.

SkyStar’s new management team introduced the Kitfox Series 6 in 2000.  The multiple versions of the Series 5 Kitfox were all rolled into a single airplane that possessed the most versatile features of all the Kitfox's.  The Kitfox Series 6 has a useful load of up to 800 pounds and a range of over 700 miles, coupled with cruising speeds of over 120 mph.  The factory’s Series 6 actually averaged 137 mph in the Sun ‘n Fun 100 Air Race in 2001, and that was with two folks on board.

The Series 6 could be configured as either a tri-gear or tailwheel airplane, and can be converted to either version after assembly is completed.  Assembly times were significantly reduced, and the Series 6 accommodates more engine types than any other Kitfox.  The look, feel and flight characteristics of the Kitfox Series 6 are like those of the most sophisticated, certified airplane, but none of the Kitfox adventure has been sacrificed.

All of the good flying qualities inherent to the Kitfox Series 5 are present in the Kitfox Series 6.  The Series 6 has a heavy-duty landing gear system that improves soft and rough field ground handling.  The Series 6 no longer used the bungee/tube landing gear that was standard on the Series 5, resulting in a more easily controlled airplane during rollout after a tailwheel landing.  Like all Kitfox's, the Series 6 retains the ability to perform awesome forward slips and is an ideal airplane for short field operations.  The Kitfox Series 6 has a refined flap system that allows the selection of two optimum flap positions.  The first notch is used for takeoff and approach. while the second notch is generally reserved for landing.  The tri-gear version of the Series 6 is very well balanced, and smooth takeoff and landing rotations are effortless.

The Model 6 kits are intended for rapid assembly. All of the welding is done at the factory, then powder coated. The wings and ailerons are fabricated in the factory, and fuel tanks are fitted and ready to be bolted in. Most components are prefabricated or preshaped and finished for quick attachment.

John and Debra McBean decided to concentrate on the Super Sport model, replacing the Classic IV.

The Super Sport kit cost $5000 more than the Classic IV did, and the 80-hp Rotax 912 engine should work well in the Super Sport.

The Kitfox Series 7 introduces a variety of both major and subtle changes in the Kitfox history of ongoing product development.  Most noteworthy is a variety of engine system enhancements that have resulted in an airplane that can cruise at over 150 mph, fly 700 miles non-stop, and heft a useful load of 700 pounds.  Through use of the remarkable Rotax 914, turbo-charged engine, the Kitfox Series 7 has a service ceiling of 25,000 feet, meaning it can operate from any public use airport in the United States, without concern over runway length, field elevation or air temperature.
Flight control improvements have lowered the landing speed and reduced aileron induced yaw.  The larger elevator and new manual trim system strengthen pitch authority and stability.  The entire Rotax engine installation has been greatly simplified, resulting in a significant reduction in assembly time.  This new installation also results in much improved windshield weatherproofing.  Like the Kitfox Series 6, which has been replaced by the Series 7, convertible landing gear, folding wings, and many custom features are standard.

While many of the Series 7 performance improvements are achieved with the Rotax 914, Continental and Lycoming engines, in addition to the popular Rotax 912S, remain very popular engine choices.  Most Series 7 improvements can be retrofitted to the Kitfox Series 5 and 6.

 

 

Kitfox 1
Engine: Rotax 532LC, 64 hp.
Max wt.: 950 lbs
Wing span: 32 ft.
Wing area: 128 sq.ft.
Wing loading: 7.42 lbs/sq.ft
Power loading: 14.61 lbs/hp
Average empty weight: 426 lbs.     
Average useful load: 424 lbs.
Max speed (Vne): 100 mph
Cabin width: 36 in.
Length (wings folded): 21 ft.
Width (wings folded): 7 ft. 10 in.
Height: 67 in.  
Average cruise speed: 75 mph
Stall Speed: 36 mph    
Seats: 2

Kitfox II
Engine: Rotax 582, 64 hp.    
Wing span: 32 ft.
Wing area: 128 sq.ft.
Gross weight: 950 lbs.
Average cruise speed: 85 mph
Stall Speed: 36 mph
Average empty weight: 426 lbs.
Average useful load: 524 lbs.
Max speed (Vne): 100 mph    
Cabin width: 39.5 in.
Length (wings folded): 21 ft. 1 in.
Width (wings folded): 7 ft. 10 in.
Height: 67 in.

Kitfox III
Engine: 912, 80 hp.
Gross weight: 1050 lbs.
Average cruise speed: 85 mph    
Stall Speed: 37 mph
Average empty weight: 460 lbs.    
Average useful load: 590 lbs.
Max speed (Vne): 100 mph    
Cabin width: 39.5 in.
Wing span: 32 ft.
Length (wings folded): 21 ft. 1 in.
Width (wings folded): 7 ft. 10 in.
Height: 67 in

Kitfox IV Classic
Engine: Rotax 912, 80 hp.
HP range: 50-100.
Speed max: 112 mph.
Cruise: 110 mph.
Range: 570 sm.
Stall: 32 mph.
ROC: 840 fpm.
Take-off dist: 200 ft.
Landing dist: 200 ft.
Fuel cap: 26 USG.
Weight empty: 495 lbs.
Gross: 1200 lbs.
Height: 75 ft.
Length: 18.42 ft.
Wing span: 32 ft.
Wing area: 132 sq.ft.
Seats: 2.
Landing gear: tail wheel.

Kitfox IV Classic
Engine: Rotax 912, 80 hp.
HP range: 50-100.
Cruise: 110 mph.
Range: 700 sm.
Stall: 36 mph.
ROC: 1300 fpm.
Take-off dist: 250 ft.
Landing dist: 250 ft.
Fuel cap: 27.5 USG.
Weight empty: 650 lbs.
Gross: 1200 lbs.
Length: 18.5 ft.
Wing span: 32 ft.
Wing area: 132 sq.ft.
Seats: 2.
Cockpit width: 39 in
Landing gear: tail wheel.
LSA

Kitfox V
Engine: Rotax 912, 80 hp.
HP range: 80-125.
Speed max: 123 mph.
Cruise: 110 mph.
Range: 605 sm.
Stall: 35 mph.
ROC: 750 fpm.
Take-off dist: 185 ft.
Landing dist: 215 ft.
Fuel cap: 26 USG.
Weight empty: 705 lbs.
Gross: 1550 lbs.
Height: 7.5 ft.
Length: 20.58 ft.
Wing span: 29 ft.
Wing area: 121 sq.ft.
Cabin width: 42.5 in.
Seats: 2.
Landing gear: tail wheel.

 

 

Kitfox Vixen
Engine: Continental IO-240, 125 hp.
HP range: 80-125.
Speed max: 145 mph.
Cruise: 138 mph.
Range: 618 sm.
ROC: 1200 fpm.
Take-off dist: 230 ft.
Landing dist: 220 ft.
Fuel cap: 26 USG.
Weight empty: 725 lbs.
Gross: 1550 lbs.
Height: 8.08 ft.
Length: 20.25 ft.
Wing span: 29 ft.
Wing area: 121 sq.ft.
Seats: 2.
Landing gear: nose wheel.

Kitfox Safari
Engine: Continental IO-240B, 125 hp.
HP range: 80-125.
Speed max: 136 mph.
Cruise: 130 mph.
Stall: 43 mph
Range: 610 sm.
ROC: 1800 fpm.
Take-off dist: 129 ft.
Landing dist: 300 ft.
Fuel cap: 27 USG.
Weight empty: 750 lbs.
Gross: 1550 lbs.
Height: 5.7 ft.
Length: 19.2 ft.
Wing span: 29 ft.
Wing area: 120 sq.ft.
Seats: 2.
Landing gear: tail wheel.

 

 

Kitfox IV Speedster
Speed max: 120 mph.
Cruise: 115 mph.
Range: 640 sm.
Stall: 39 mph.
ROC: 1200 fpm.
Take-off dist: 200 ft.
Landing dist: 240 ft.
Engine: Rotax 912, 80 hp.
Fuel cap: 26 USG.
Weight empty: 640 lbs.
Gross: 1200 lbs.
Height: 6.64 ft.
Length: 18.33 ft.
Wing span: 28.66 ft.
Wing area: 116.8 sq.ft.
Seats: 2.
Landing gear: tail wheel.

Kitfox Super Sport
Cruise: 120 mph
Stall: 41 mph
Range: 700 sm
Rate of climb: 1300 fpm
Takeoff dist: 290 ft
Landing dist: 270 ft
Engine: Rotax 912S, 100 hp
HP range: 80-100 hp
Fuel capacity: 18 USG
Empty weight: 750 lb
Gross weight: 1320 lb
Length: 19.8 ft
Wing span: 32 ft
Wing area: 132 sq.ft
Seats: 2
Cockpit width: 43 in
Landing gear: nose or tail

 

 

Kitfox Lite Squared

Kitfox SLSA