Engineering News - February 2007
Cutting-edge local entry into global niche aircraft market
By Keith Campbell, senior contributing editor
Pictures: Colin Bennett
South African Company, Slick Aircraft (Pty) Ltd is planning to display its new single-seat piston-engined aerobatic sports aircraft, the slick 360, in the US during March and April, and also at the renowned Sun-‘n-Fun airshow.
Manufactured at Wonderboom airport, in Pretoria, by specialist manufacturer, Global Composite Solutions (GCS), the South African designed and developed Slick 360, which is one of the first all-composite aerobatic sports aircraft to enter production anywhere in the world, has already aroused a lot of interest in the US.
“But the Americans want to see the aircraft fly, and to fly it themselves, before they place any orders – hence, the decision to go to Sun-‘n-Fun”, explains GCS workshop manager, Chris Hattingh, who oversees the manufacture of the aircraft.
To date, one prototype and three production aircraft have been built and flown; two more aircraft are currently being assembled, and should fly in a few weeks – one of these is the first Super Slick, intended to compete in the international series of Red Bull Air Races, featured on TV.
The programme has its roots in 2002 when champion South African aerobatic pilot Glen Dell realised that the sport in South Africa was too dependent on once good but now obsolete designs and that there was a need for a twenty-first century aircraft for what had become a twenty first century sport.
Dell approached Hattingh to see if GCS could manufacture such an aircraft. “The Slick 360 is definitely our design, it has been inspired by other aircraft”, affirms Dell. “Inspiration came from an American aircraft, the Lazer, which had later been further developed by a German designer, Walter Extra, resulting in an aircraft called the Extra 230,” he reports. But both the Lazer and the Extra 230 used wooden wings, including the main wing spar, and by the 1980’s, wood of a sufficiently high quality had become difficult to obtain at suitable prices, so ending production of the Extra 230 (Both these aircraft had fuselages built around tubular metal frames).
“So there was a gap in the market, “highlights Dell.
Although the prototype had an all-composite wing from the start, its fuselage was built around a tubular metal frame, like the earlier designs. “The prototype was so successful that we decided to go into production and make the aircraft all-composite, for various reasons,” he states.
“Weight was not one of them – a composite fuselage is no lighter than one built on a tubular metal frame; nor are composites stronger than a tubular frame,” he adds. “But the key is the shape of the fuselage that you can get from composites – they give us a more refined, more streamlined, more aerodynamic shape; and composites give us superior rigidity as well,” he elucidates.
“Going for composites was the big decision we made, and it has allowed us to give the aircraft as clean a design as possible,” he points out.
The structural engineering for the aircraft was carried out by Francois Jordaan.
The aircraft is powered by a US Lycoming AEIO 360 four-cylinder piston engine, producing 230 hp at sea level – this is an engine specially produced to power aerobatic aircraft. ‘AE’ stands for aerobatic, ‘I’ for (fuel) injection, ‘O’ for opposing (it is an opposing engine design), and ‘360’ for a capacity of 360 cubic inches (about 5 litres).
Concerning the manufacturing programme and process, the programme started in 2003. “The prototype flew on February 7, 2004, and was then used to win the South African National Aerobatic Championships that June, while being flown by Dell,” recounts Hattingh. (Dell went on to win the Advanced World Aerobatic Championships in Sweden that August, flying an Extra 230.)
The aircraft are 90% composites – the only metal parts are the control rods and the tubular engine support frame. “The composites used in the Slick 360 are a mixture of 70% carbon fibres and 30% glass fibre. The Super Slick will be 100% carbon,” he clarifies.
The moulds used to produce the composite components of the aircraft were constructed by GCS. The company also has its own metal shop, although it outsources the laser cutting of certain components to a specialist enterprise located in an adjacent Pretoria suburb.
Production aircraft number six is now being built. “We hope, depending on orders, to be able to make up to eight Slick 360’s, plus another five Super Slick’s each year,” he states.
The two companies – Slick Aircraft and GCS are also working on a composite two-seat elementary training aircraft, aimed at replacing the ageing Cessna designs currently used by South African flying schools to train private pilots.