Bushbaby

Flight test

There's little as beguiling as a rough-hewn, dusty airstrip miles from anywhere with little protection from a searing sun. Few of us have not longed for the life of a bush pilot. Unfortunately Africa is large and Cessna 180's are slow and not altogether cheap. Forget speed for a moment; in the corner of a Secunda engineering shop and one of the local airfields' hangars, a duo of Gautengers is building the ultimate Camel Man accessory. It's modestly called a Bushbaby. There's little new behind the concept of a mini bush plane, after all, their airframe design owes more to nineteen thirties technology rather than Rutanesque composites. Merely tracing the Piper Cub's heritage will prove this theory. Nevertheless, using slick marketing techniques, latest engine developments and packaging the lot together to make an affordable and 'easyish' kit has created a mini fashion. This new fashion followed the launch of Dan Denney's hugely popular Kitfox, first flown in 1984. With a wing designed by well known aerofoil specialist Harry Riblett, Denney first started producing the diminutive sport plane at a factory in Boise, Idaho. Six aircraft were sold in the first year. It wasn't long before others copied the concept. Over 2,500 Kitfox kits have been sold to builders in 40 countries and over 1,400 have been completed. Denney eventually left Kitfox to start Avid Aircraft, producing another tiny high wing sport plane much like his original aircraft. This is known as the Avid Flyer. Nowadays, Kitfox and its facsimiles are built world wide, the most recent version being a licensed built model constructed in the Czech Republic. Australia sells its own Kitfox-type aeroplane and three years ago, South African Nols De Bruin of Kitplanes For Africa, Secunda, began supplying the Bushbaby. The Bushbaby is unashamedly a Kitfox look-alike. Although the company is now owned by the Secunda businessman Monty Jefferies, two owners shook their heads ruefully and became tight-lipped about differences. When Kitfox was born, a big the company's performance during the pre Jefferies era. It was clear that Kit Planes For Africa were keen to emphasize a new approach to customer service and were at pains to reassure owners and those considering such an aircraft, that any problems of the past were now well behind them. Whilst the Bushbaby is almost identical in appearance to Dan Denneys earlier masterpiece, there are some notable thing was made of its Chrome molybdenum, tubular airframe. In order to make the Bushbaby less expensive and easier to repair locally, the fuselage has been finished using a common or garden SAE 10/10 carbon steel frame. To match Chrome Moly's higher tensile strength, Kit Planes For Africa use a slightly thicker tubing, adding about 101bs to the Bushbaby's basic weight. Moreover, carbon steel is less brittle and instead somewhat more 'bendy'. Any reduction in tensile strength however, has been made up for by adding triangular cross sections to the already sturdy fuselage frame.

Kitplanes For Africa rightfully stress the ease of repair or replacement found with the locally manufactured steel and Jefferies claims that the cost reduction amounts to a useful R10,000 per aircraft. Lets not forget that thousands of Piper Cubs and Tiger Moths were made using carbon steel airframes. I'm happy to fly with it. Monty Jefferies contracts local manufacturer Waypoint to make the kits. Veldkon is run by the Botha's, who are a well-known Secunda aviation family. Son jurie, who runs the engineering firm, has his own Bushbaby, the 16th one made. Like Kitfox, the Bushbaby is supplied purely in kit form. Although buyers can choose to have their aircraft made for them by a number of outside specialists at a cost of up to R25,000, most choose to do it themselves. Kitplanes For Africa foundation is the supply of 4 basic assemblies known as Firewall Back units: the fuselage kit, wing kit, landing gear kit and cover and finish kit. Combined, they cost a little over R52,000 depending on final specification. Whilst many purchase the entire kit plus the engine, propeller, gauges, instruments and radio's in one fell swoop, the task can be eased by buying assembly kits in stages.
Where would we have been without Ski do engines, yes, the immortal Rotax. Although almost unheard of in Africa, the Ski do is one of those wonderful anti environment fun things that are designed to traverse snow at great speed. They are traditionally powered by Rotax engines. The Rotax was first seen in aviation during the early eighties powering early microlights. Back then, 40 horse power was almost enough to launch an Eipper Quicksilver. The motors didn't acquire a great reputation for reliability, which was perhaps due to the category of aircraft they were fitted to rather than any inherent fault. Early Rotax 447's came delivered with only single ignition and a single carburetor. Those choosing to fit one to a flying machine had to rig their own belt reduction gear. Nowadays, Rotax has moved into the heady realm of general aviation, and current 447's, 503's, 582's and 912's all come with dual ignition, dual carbs, integral gearbox and other nineties accoutrements. Although Bushbaby builders are given a choice of power plants including the earliest Volksie Beetle derivative, most decide on Rotax's 80hp, 4 stroke, 4 cylinder air/water cooled engine. Notwithstanding their lawnmower yell, Rotax's are the engines of choice for the Kitfox family of aircraft costing about R55,000 ready to take away. Those not wanting to spend so much will find the VW engine nearly R30,000 cheaper although there is a weight penalty of nearly 20 kgs. Homebuilders know that manufacturers quoted completion times are usually very optimistic. According to builder Dennis Tavares, whose aircraft is on this issue's front cover, Kitplanes' For Africa is no exception. Although the manufacturer claims only 450 hours are needed, an inexperienced Bushbaby builder will probably take twice that time. Couch potatoes, unless they have the twenty five grand for someone else to do the job, might find the task too burdensome. Jefferies recommends that the builder needs to be a handyman type with a reasonable set of tools including a drill press. To make matters even handier an angle grinder, power file, pop rivet gun and electrical drill come in useful. Once 75-percent completed, the time is right to approach the Department of Transport for a registration number. The Bushbaby can be completed as a Microlight or as an LS1 category aircraft. To fall into the former it has to weigh less than 500kgs all up. Before the fuselage is covered, it's mandatory that the aeroplane undergoes a re-covering inspection. This is important as it should unearth any monumental cock-ups before the structure is hidden from view forever. The inspection has to be carried out by an 'DCA approved person' and takes between two and three hours. This is followed by a weight and balance check and a then a final three to four hour 'final signoff'. Mercifully the DCA require only a single logbook for an LS1 category aircraft. With this, a weight and balance certificate and the final signoff letter, the Department will issue an Authority to Fly certificate for a minimum of 40 hours before allowing the builder to persuade passengers to benefit from his handiwork. The 40 hours must be completed within a six-month period with the added proviso that the aeroplane cannot be flown more than 50 nautical miles from its home base without special permission.

Because this type of aircraft is homemade, it's unlikely two will be the same. For instance, Jurie Botha has placed his engine instruments above the windshield in the cabin roof, just like, ermm, a Boeing. Whilst this may not be ideal in the event of sudden deceleration, it does free up panel space. Jurie, in line with his family's Cessna 182, has used the space to install a good quality panel mounted GPS and a neat cutout on the glare shield to drop in a typical handheld radio. The radio thus takes on the appearance of a smallish panel mount unit, directly facing the passenger. Indeed, it's inevitable that with so much tubular steel around, a good portion of it is exposed inside the cabin very handy to attach things.
Seating is another item which is subject to personal taste. Dennis Tavares made the decision to upholster his cabin using traditional sitting room fashion at the expense of headroom. His aircraft is therefore more comfortably equipped for longer trips including the annual pilgrimage to Margate. Standard fare is a glass fiber moulding. Naturally, many things can't be changed without a major redesign. The Bushbaby nevertheless offers a choice of wing section STOL or Speed.
In line with maintaining the aeroplane's 'bush' appeal, most owners opt for the STOL version. Like most things in aviation design, there's no avoiding a compromise. The STOL wing has a 10-15 mph lower stall speed than the Speed wing. In a classic swings and roundabouts situation, it is also 10-15 mph slower in the cruise. The difference lies in a greater STOL wingspan of 1,3 meters. Whilst this may seem a harsh price to pay for a lower stall speed and therefore a shorter landing run, it must be remembered that the draggy ailerons and flaps flaperons also extend by a similar amount.
In the three years in which the 46 kits have been ordered, modifications have been made to improve comfort and beef up an already strong structure. From airframe 11, the forward spar carry through tube was replaced by a square section support and the vertical fin was also beefed up. The manufacturer then discovered that the airframe itself was extremely over engineered and when additional cross braces were incorporated, it enabled the use of slightly narrower steel tube 12mm down to 1Omm. From airframe number 16, the fuselage was widened to provide room where it's needed most at the shoulders.
Bushbaby kits are made in batches of 10 and the latest batch beginning airframe number 46 has included a softer rubber undercarriage bungee, which absorbs a higher shock factor during landing.
It's very easy to be lured into believing such a sweet tiny aeroplane is a pussycat to handle. Moreover, it pays to bear in mind how light the airframe actually is. It therefore follows that the human occupants, especially when two up, contribute to a high percentage of the plane's mass which in turn significantly affects performance. At only 500kgs gross weight, windy conditions on the ground and turbulent air will be major factor in controllability The light weight of these aircraft, like all microlight sized aeroplane's, essentially makes them fair-weather friends, which, after all, is what the designer had in mind in the first instance.

The cabin doors swing upwards using gas support struts. Botha's aircraft has a detachable co-pilots stick, which goes a long way in easing entry and exit. Getting into the aircraft is somewhat easier than its size suggests. However it involves placing your bum in first followed by both legs. The process is helped by grasping one of the airframe tubes that run through the cabin overhead. On a hot day the doors can be either detached completely or left open. Using the choke for a cold start, the Rotax whirrs easily into life at the twist of a key. Once the after start checks are complete, it's wise to be mindful of weight factors. Many Bushbaby's are equipped with 50 liter fuel tanks in each wing. Full fuel therefore takes up 158lbs or just over 70kgs, allowing 180kgs for occupants and baggage. Whilst this is plenty, two heavies would have to take somewhat less than full fuel to stay within the maximum allowable payload. At 16 liters per hour, the Rotax will stay humming for well over 5 hours. It's unlikely that two people will want to sit in a Bushbaby for that period of time at one stretch, so a fuel compromise with two large occupants would be a small price to pay.
Although the aircraft can be custom built, most Bushbaby's have brakes on the pilot's side only. With a fairly short fuselage, ground handling requires care. The tail wheel set-up is again a matter of personal choice though a tail wheel lock isn't yet an option. With a good level of concentration, the little bush plane won't swap ends. However, its light weight, fairly narrow track and vertical fuselage sides conspire to make it sensitive under crosswind conditions almost to a slow walking pace. Whilst the Bushbaby has a high tolerance to crosswinds with some pilots happy to land with a 15 knot component, pilots will need to have their finger out.

The view over the nose is adequate, requiring only slight weaving to see clearly in front. Two occupants dramatically increases the takeoff run and although the company's brochure boasts a 95 meter run for the Speed wing version at sea level, the aeroplane requires at least 200 to clear the ground at typical Highveld density altitudes. Few light aircraft will come near to equaling this takeoff performance however.
At full power, the tail comes up at just under 20 knots and the aircraft lifts off comfortably at 45 knots with two on board. It's immediately apparent that the aeroplane possesses very sensitive controls, particularly in the rolling plane.

The effect is perhaps more noticeable on a hot, turbulent day. Harry Riblett, when designing the wing, made a decision to install 'Flying Wing Controls'. Although called 'Flaperons' by light plane manufacturers nowadays, this description isn't strictly true.
The essence of a Flying Wing Control is a flap/aileron system suspended clear of the wing trailing area. In the Bushbaby, the ailerons and flaps form a single control surface hinged below the trailing edge. The flaps are adjusted with a cockpit floor mounted lever. The result is high drag at cruise speeds, but powerful controls at landing speeds. There's nothing new about this and perhaps it's most famous user was Hugo Junkets, who employed it on the JU52.
The best climb rate at gross weight on the Highveld is about 400 feet per minute. There's little reason to doubt brochure figures of 800fprn for the Speed wing version at sea level. The STOL wing version performs better by an extra 200fpm at sea level.
The Bushbaby is challenging to fly accurately. To maintain balanced turns, rudder input is essential and in this respect it's not unlike a Tiger Moth. Full stick deflection is hampered by the occupants legs an unwelcome quality that can be alleviated by fitting an adjustable bell crank to de-sensitize the ailerons. Control response is instant with easy and light inputs in all axis. The ailerons, whilst powerful, have a slightly disconcerting resistance at the neutral point when moving between opposite deflections.
However, the aircraft displays a tendency to return to straight and level flight if the controls are released during a turn.
A Speed wing Bushbaby stalls at 36 knots, the STOL wing version at an astonishing 26 knots. The stall is predictably benign with the aircraft showing little tendency to drop a wing with or without flap.
As the manufacturer promises, the Bushbaby is a great deal of fun. Its control response and ample power will ensure hours of enjoyment, particularly in mastering tail dragger landing techniques. Whilst owners can expect between 90 and 100 miles per hour at Africa's density altitudes, speeds are not going to be the primary concern of builders. The Rotax will turn at 5,400 rpm giving a maximum 80hp power for 5 minutes. Thereafter, the engine is best throttled back to 5,00Orpm representing about 78hp of continuous power. At this setting the owner may expect a cruise of around 90 mph. The reduction gearbox limits propeller speed to a maximum 2500 rpm.
Landing the aircraft calls for a good level of concentration. Enough, that many owners prefer to wheel them on. The Bushbaby is happy with three pointers and this method is often used when the shortest landing run is required. Figures here are largely academic as the aircraft has the capability to operate into some very small areas. Monty Jefferies points out that the aeroplane is ideal to operate from a good-sized plot. Whilst this may not be music to the ears of the Department of Transport, it's a tantalising compulsion in every pilot's dream to have their own airstrip adjoining their pub.

In homebuilding terms, the Bushbaby represents a wonderful mix of fairly effortless construction at a reasonably low price. The separate kit assemblies make purchasing a painless task, if you can't wait to save the full purchase price. Moreover there's no shortage of help as the country has a plethora of owners who are always ready to share their experiences. Building aeroplane's isn't everyone's cup of tea and those wanting a ready-made example are best advised to call Monty who has ready knowledge of when aircraft come onto the market and the ability of their builder. The Bushbaby breaks no new ground, rather it continues a wonderful fashion set up by Dan Denney in the early eighties. Its combination of ease of manufacture and locally sourced building materials should make it a winner, as the production figures have proved.

Kit Planes For Africa has modest plans for the future. Although buyers won't be able to order complete aeroplane's from the factory for some time, Monty is aiming to further establish local kit sales and then seek export markets, in particular Europe and Australia. In South Africa, the aircraft has been bought by a mixture of owners ranging from existing weight control microlight pilots wanting three-axis control to farmers and doctors.
Those completing kits will be able to look forward to R200 MPI, parts costing a fraction of conventional aeroplane parts prices and with it's folding wing, inexpensive hangarage. According to Dennis Tavares, his machine costs a minimal R80 per hour to operate including insurance, fuel, engine over haul allowance and regular maintenance.
Can't be bad can it?