Most people who own light aircraft buy them fully assembled, but this isn’t the only option. The Airplane Factory lets the buyer purchase their Sling type two or four-seat aircraft in kit form and lets them be the builder.
Visit a typical metal fabrication shop and you’re likely to see more ways to shape, cut and join metals than you can count on two hands. Bending, punching, flaming, notching, sawing, welding and many more. In most small shops, the owners, managers and employees are regular guys who love to run machines and get their hands dirty, turning flat sheets of metal or straight lengths of tube into useful products. For many it’s not just work, but greatly satisfying work, turning raw materials into components or subassemblies that will become a finished product that someone wants or needs.
Visit an aircraft hangar and you’ll probably hear pilots telling stories about spectacular flights and using abbreviations and opaque terms that beg explanation, terms such as wind shear, stall speed, artificial horizon, VFR (visual flight rules), IFR (instrument flight rules), and the like. My best is ‘Deadhead’: A deadheading pilot or flight attendant is one who is repositioning as part of an on-duty assignment. Essentially, they’re flying as a passenger while on duty. Crop dusting is another but you are going have to do some research on that one.
The company introduced a higher spec four seater – the Sling 4 TSi model in 2017
Nevertheless, these pilots are also regular guys and they make a living or have a hobby that isn’t for the faint of heart. It takes more than a little courage to pilot a ‘vehicle’ on a lengthy trip that has to fight gravity every mile of the way, or land one in conditions that are testing knowing that you are in control of all those others that are on board your ‘vehicle’.
Since the Wright brothers’ first successful powered flight in a fixed-wing airplane, the aircraft industry has spawned a dizzying array of specialised airplanes, each with features that correspond to the needs of the aircraft’s role. Bombers have vast wing surfaces to develop the lift necessary to cart around thousands of tons of explosives. Fighters have much smaller wing profiles to reduce drag, emphasising speed and maneuverability. Patrol aircraft use a blend of offensive and defensive weaponry to hunt submarines and ships in hostile waters. Spy planes rely on high-altitude, high-speed flights to carry out surveillance undetected.
Currently the company is producing two factory built planes a month and six full kits per month. To date they have sold over 280 Sling 2 versions and 160 Sling 4 planes
Likewise, civilian aircraft have advanced terrifically since 1903. The largest planes can carry 800 passengers at a time. The A380-800 is certified for up to 868 passengers (538 on the main deck and 330 on the upper), achievable with a one-class configuration. Airbus references a “comfortable three-class” 544-passenger configuration. This big, lumbering, stable aircraft usually has a turn radius measured in miles. An acrobatic pilot in a small, maneuverable stunt plane can perform a couple of loops in a distance less than the wingspan of the largest passenger plane.
When you visit The Airplane Factory, which is based at the Tedderfield Airpark in Eikenhof, just south of Johannesburg, you’re likely to meet people who are either design engineers, fabricators or pilots. In the case of Mike Blyth, Director and one of the founders of the company, he is all three of them. Throw in electrical engineer, machine operator, quality inspector or the draughtsman that operates the high end CAD software and you will have a more complete picture of Mike Blyth’s capabilities and his personality.
Blyth studied mechanical engineering and architecture before becoming involved with the aviation industry at the age of 30. Since then he has been professionally involved with the industry. He admits that he is a pilot with the spirit of adventure in him and is equally passionate about how the 17 000 rivets and 2 500 components that hold his ‘babies’ together, are manufactured. Put him in front of the computer in the drawing office that is running the high-end design software programme or get him to operate his latest capital equipment acquisition, a Durma press brake and he is equally skilled and at ease as he is flying his company’s Sling 2 and Sling 4 aircraft.
There is a full time staff of 135 people and the complex includes all the amenities necessary for the production of high-quality Slings of which 80% of production is exported either in a kit form or a complete build
A Sling being assembled
Blyth is a pioneer of early microlight aviation in South Africa and has been involved in the aircraft business designing, building and selling aircraft for 34 years. Blyth is a past aviation world champion and has received numerous awards both for his contribution to aviation in South Africa and his aviation feats, as well as the films he has made to record them. These feats include circumnavigating the globe in the company’s Sling 2 and Sling 4 aircraft, not once but three times, and are part of his impressive CV.
“Many positions in aircraft manufacture require a bachelor’s degree within a broad range of engineering or science fields in addition to aeronautics or astronautics, such as mechanical, electrical, structural, materials and even civil engineering. Other jobs might require training in systems safety, human factors, air-vehicle integration or aesthetic design. Most people entering the field on the manufacturing side are expected to have CAD/CAM and CNC training and capability.”
“When you have none of these skills you have to be able to assemble the individual experts, manage them and encourage them to develop your idea of manufacturing one of the most exciting light performance aircraft in the world. This is what I did in the beginning but I made it my mission to learn and be competent at every aspect that is required to design and manufacture an aircraft.”
Airframes being fabricated
The new Durma AD-S 37175 press brake that was purchased four months ago from Durma South Africa
“Most aircraft designers and engineers aren’t pilots, and it’s not typically required, but any direct benefits aside, having a pilot’s licence demonstrates an enthusiasm for the field that helps individuals stand out among colleagues, and is helpful in having a connection with customers. Likewise I needed to do the reverse and demonstrate to all my colleagues that I knew what I was talking about.”
“Our journey began in 2005. I had been sketching aircraft from a young age always with the idea to become a pilot. Through my years of experience of flying many different types of aircraft I had a very good idea of what would constitute my perfect light aircraft that could be manufactured locally but also have international appeal. I needed a backer and James Pitman was the man I needed. A lawyer with a BSc in physics, James worked at a uranium producing company as the legal adviser. When the company was sold, he made what he calls ‘a quick buck’. Fiscally secure, James went back to his passion for flying and attained his Private Pilot’s Licence (PPL). Together we formed The Airplane Factory.”
“By 2008 the two-seat Sling 2 prototype was built and test flown. We flew it for 20 hours then started re-designing components with which we were not satisfied. Further test flying left us still not satisfied so we scrapped this prototype and started again. Our next developmental prototype attained what we believed was the perfect control harmony of pitch, roll and yaw.”
Where possible The Airplane Factory manufactures every component in their factory including composites of glass fiber and carbon fiber
Mike Blyth, Director and one of the founders of The Airplane Factory
“James and I then decided to fly the production prototype Sling 2 from Johannesburg to one of the world’s biggest airshows – the Oshkosh Airventure Airshow in Wisconsin US – and then continue with our journey westwards and circumnavigate the globe. This journey took us over one calendar month, starting on 18 July and ending on 27 August 2009 and was a first for any South African. It was also a major step forward for the company.”
“Covering more than 45 000 kilometres, we stopped in 14 countries, including Sao Tome, Guinea, Brazil and Malaysia. The amazing thing was that we could design and develop an aircraft ourselves, get into it and in 40 days zoom all around the world in this little aircraft we dreamed of manufacturing,” said Blyth.
“The publicity and excitement garnered from our adventure and the performance of the Sling 2 put us on the map and in the spotlight. Initially we were going to be the design house only but soon started to manufacture. Start-up costs were huge and we had to import 90 per cent of the components, including the 1 200cc Rotax engines.”
“In 2009 we began designing a four-seat version. The Sling 4 concept emerged from the performance of the standard Sling 2 during our 2009 circumnavigation of the earth.”
The Airplane Factory total space under roof is 3 500m² and this also includes a maintenance ‘hangar’. They are currently investigating acquiring more factory space so as to allow for expansion of the composites manufacturing department
The Airplane Factory uses approximately 37 sheets of 1.2 by 3.7 metre size aluminium sheets per aircraft
“Conceived as a 600kg maximum All Up Weight light sport aircraft, it was soon clear that, even with a normally aspirated 100HP/75kW motor, the standard Sling 2 was able to climb and perform well right up to 970kg.”
“The first consequence is that The Airplane Factory Team performed all the required tests and approved the standard aircraft at 700kg MAUW. We also simultaneously commenced work on development of a light 4-seat version of the same aircraft.”
“The chief differences between the Sling 2 and the Sling 4 are the wing size, the engine and the centre fuselage arrangements. Where the standard Sling 2 customarily uses a 100HP/75kW Rotax 912 ULS or iS engine, the Sling 4 is fitted with the 115HP/85,7kW turbocharged Rotax 914 UL engine. Although a 15HP/11,2kW difference doesn’t sound like the world, the turbocharged engine gives full power at up to 15 000 feet, at which altitude the 100HP/75kW would only be delivering approximately 55HP/41kW. So, on a hot day the swing in power between the 912 ULS and 914 UL engine is in the vicinity of 36%, not just 15%.”
To fly the Sling LSA you need a National Pilot’s Licence, which allows you to fly an aircraft, when fully loaded, weighing 600kg or less. You need a PPL for the four-seater Sling 4, which has a maximum take-off weight of 920kg. The Sling 2 is the 700kg version of the Sling LSA and to fly that you also need a PPL. The Sling 2 is popular with flight training schools, and it’s also an excellent transition to building hours towards a commercial pilot’s licence.
Fabrication of the wings
Approximately 17 000 rivets and 2 500 components are used per aircraft
The company introduced a higher spec four seater – the Sling 4 TSi model in 2017. It is equipped with a 141HP/105 kW Rotax 915 iS turbocharged engine with a cruise speed of 145 knots at 9 000 feet.
“All models of the Sling are designed as low wing aircraft. Currently in development are high wing versions of the aircraft and we hope to fly a prototype by the end of the year and go into production with our new products in 2019.”
The Airplane Factory utilises numerical control manufacturing and computer-aided design in its aircraft design and production processes. The factory site at the Tedderfield Airpark comprises nine ‘hangars’, each one carefully positioned to house fabrication, sub-assembly, final assembly, composites and the paint shop, as well as an administration ‘hangar’. The airstrip runs parallel to these ‘hangars’ allowing for easy access for test flying.
“We don’t need a control tower here as we have clearance to 2 000 feet and the only other occupants of the airpark are recreational flyers. They occupy the buildings on the other side of the airstrip. Our total space under roof is 3 500m² and this also includes a maintenance ‘hangar’. We currently need more factory space so as to allow for expansion of the composites manufacturing department.”
The paint shop at The Aircraft Factory
The light aircraft market only accounts for about 2 500 builds a year
There is a full time staff of 135 people and the complex includes all the amenities necessary for the production of high-quality Slings of which 80% of production is exported either in a kit form or a complete build. Kit form planes are offered to save on costs like transport. The kits come in an almost completed state. The control surfaces are nearly finished, wings are virtually complete, fuel tanks are finished and sealed, holes are predrilled, and everything requiring driven rivets is prefabricated at the factory. The quick-build kit comprises six subassembly kits, such as the empennage and wing kits.
The factory has taken an innovative approach to helping builders by providing extensive building manuals. Even all the tools, glues and wires needed for the assembly process are provided with the kits.
Currently the company is producing two factory built planes a month and six full kits per month. To date they have sold over 280 Sling 2 versions and 160 Sling 4 planes.
Factory built planes have a four month waiting period and depending on the builder a kit can take between 800 and 1 000 hours to assemble.
“From the beginning we wanted to manufacture a plane in aluminium because of its strength properties. We try to purchase locally but the majority of the structural materials that we use, for example the aluminium sheets that we form and process, are imported because the specific grade of aluminium is not made in South Africa. The two grades that make up the eight tons that we process in a year are alloy 6061-T6 and alloy 2024-T3. These grades conform to the aerospace subgroup of the society of engineering standards based in the US, which the entire EU and NATO is signed to.”
Fabrication of material at The Airplane Factory includes a Euromac punching machine supplied by CML Machine Tools
Between The Airplane Factory partners Mike Blyth and James Pitman they have taken their aircraft around the world three times
“Each sheet of aluminium is pre punched to accommodate the rivet holes before it is hydro-formed to fit the shape of the frame. Other components are bent on our new Durma AD-S 37175 press brake that we purchased four months ago from Durma South Africa. Other capital equipment in this department includes a Euromac punching machine supplied by CML Machine Tools, an Amada tool sharpener and a Multicam router.”
“We use approximately 37 sheets of 1.2 by 3.7 metre size aluminium sheets per aircraft.”
“Where possible we manufacture every component in our factory including composites of glass fiber and carbon fiber. All these materials are also imported as are the engines that are imported from Austria, the propellers from either the US or New Zealand and the Garmin flying instruments. These instruments make up between R180 000 and R300 000 of the costs depending on what the client wants included. All other electronic components are also imported.”
“We also have our own paint shop that includes a curing oven. At this stage we are happy to offer the clients a colour coordination of their own choice. Priming is done to prevent corrosion.”
“Currently we are outsourcing the machining of nearly 200 components but this could change in the future as it becomes more cost effective for us to bring machining inhouse.”
Stringent testing and quality control
“Each component passes through at least five quality checks and everyone is barcoded for traceability. Everything is checked and double-checked. We can’t afford to have a failure. We want to have a flawless safety record.”
The Airplane Factory utilises numerical control manufacturing and computer-aided design in its aircraft design and production processes
Throughout 2017, The Airplane Factory set out to have their processes certified to the ISO 9001:2015 standard. Toward the end of 2017, they were audited by Bureau Veritas and are now happy to announce that as of February 2018 they received their official ISO 9001:2015 certification.
Blyth also does a mandatory inspection of a newly built plane before it is taken on a test flight. Thereafter at least five hours of testing is done by the company’s test pilots. According to Blyth, such meticulous inspections and quality control measures have made the Sling one of the most reliable light sport aircraft in the world.
A recent development at The Airplane Factory has been an agreement signed with a Belgian company called Sonaca Aircraft to build a two-seat, single-engine airplane named Sonaca 200. The airplane is designed for the training market and is based on the Sling 2 design. The company is already building a sixth airplane for Sonaca.
Besides being sleek and sexy without sacrificing safety one of the biggest advantages of the Sling is that it takes petrol, otherwise known as mogas, which is cheaper than aviation gas (avgas) and jet fuel. In Accra, Ghana for example, avgas could cost R78 per litre. So it would cost you R30 000 to fill up the plane. But at the same time normal mogas could cost R6 per litre. So there’s a huge difference in price.
It is also economical. The 150-litre fuel tank in the Sling 2 can give a pilot up to 11 hours of flying and the 168 litres on the Sling 4 as many as eight hours. This translates to 2 200 kilometres (Johannesburg to Cape Town and then back to George) in the two-seater and 1 800 kilometres in the four-seater.
The Airplane Factory has invested in more fabrication equipment. This includes the installation of a Euromac Flex STX 12 punching machine supplied by CML Machine Tools
Between Blyth and Pitman they have taken their aircraft around the world three times. Some legs they have done together but other legs have been with other pilots including former production director Jean d’Assonville. The longest stretch the plane has flown was in the Sling 4, and was undertaken by Blyth and d’Assonville in 2011.
They returned home after a grueling 6 222 kilometre 27 hour leg from Rio de Janeiro (Brazil) to Cape Town (South Africa) arriving on 23 September 2011. Their amazing flight over the Atlantic passed over Tristan da Cunha, the world’s most isolated island.
They wanted to keep the Sling 4 as close to the standard product as possible but due to the distances they had to travel over oceans, jungles, deserts and ice caps they had to make a couple of changes to the fuel tanks. They increased them from 184 litres to 450 litres (giving 20 hours of endurance). For this last leg from Rio extra tanks were fitted on the back seat, which increased the capacity to 780 litres.
Besides Blyth and Pitman, James’ brother Andrew is also a shareholder at the company. Other key people in the company include aeronautical engineer Terry Musiker.
“Building aircraft has typically been dominated by large factories in the US and Europe so taking on and trying to break into this market, some would say, is foolhardy. Yes if you want to build large commercial or conflict type aircraft. But in our space of light aircraft manufacture the barrier to entry is far less. We as South Africans have a rich heritage of engineering design and more importantly we are not scared to take on the world. Look at the multi-purpose single propeller driven reconnaissance and surveillance aircraft AHRLAC that has made huge impressions in the rest of the world.”
“The light aircraft market only accounts for about 2 500 builds a year, so we have plenty of space to grow,” concluded Blyth.
For further details contact The Airplane Factory on TEL: 011 948 9898 or visit www.airplanefactory.co.za