It is generally, if not universally, accepted that the height of flying skill is embodied in the test pilot and the apex of air engineering ability in the flight test engineer. Despite huge advances in computer modelling and simula- tion, test pilots and flight test engineers still have a crucial role in aviation/aerospace research and development (R&D), for not everything can be modelled and certainty can only be obtained by real-life test flights. Test pilots and flight test engineers, however, are not and have never been daredevils. They would not live long if they were. Rather, they display a combination of first-class flying skills, careful preparation, thorough planning and highly analytical minds – in a phrase, supreme aviation professionalism.

All countries which produce aircraft, or seek to modify aircraft, or manufacture any system designed to be dropped or launched from an aircraft, or want to have an autonomous ability to integrate new systems on to or into aircraft, need test pilots and flight test engineers. South Africa was and is no exception. And yet little public attention has ever been paid to this country’s test pilots and flight test engineers.

It is necessary to highlight that flight test aircrew are at the top of a pyramid of expertise and support, without which they would not be able to function. There are the maintenance personnel which keep the specially instrumented flight test aircraft flying. There are the aerodynamicists and aeronautical engineers who carry out the research and modelling and wind-tunnel testing that precedes (and often parallels) any flight test programme, and who participate in the analysis of the results of the test flights. These experts are often based at the Council for Scientific and Industrial Research (CSIR) – which has an aeronautics research competence and owns and operates the country’s wind tunnels – or at universities. There are also the scientists and engineers who observe the test flights from the ground, on instrumented test ranges, and the technicians who maintain and calibrate these ground observation systems. In the case of South Africa, the main such facility is the Overberg Test Range, near Bredasdorp, in the Western Cape, which is owned and operated by State-owned defence industrial group Denel. Denel OTR, as it is designated, also serves foreign clients who seek to take advantage of the area’s sophisticated and state-of-the-art flight test facilities.

The Golden Age

The stimulus for the development of experimental flight test in South Africa was the creation of the local aerospace industry, initially with R&D by the CSIR. The Atlas Aircraft Corporation (later absorbed into Denel) was founded in 1964. These developments were the result of fears, later realised, by the then National Party government of arms embargoes being placed on the country because of its apartheid policies.

“Before the sanctions, South African Air Force (SAAF) test pilots were trained overseas, initially at the Empire Test Pilots School, in the UK. There were very few SAAF test pilots – on average, less than five at a time – as, in those days, South Africa bought overseas aircraft and systems, so there was little need for local flight testing,” explains former test pilot Colonel George Muller SAAF (retired). “Increasing local production and design created a requirement for a larger local test pilot corps.”

Oddly, however, South Africa never created its own test pilots training school. Despite sanctions and embargoes, the SAAF was able to get its test pilots trained overseas, at civilian test pilots schools. (All South African test pilots were and are serving or former SAAF pilots.) In addition, some foreign test pilots came here to do some of their training, using aircraft avail- able in South Africa. The overseas countries may have permitted this in order to gain some insight into what was happening in this country’s aero- space sector and air force. “There was unofficial liaison with overseas test pilots schools. That allowed us to do a lot of benchmarking in those days. With difficulty, we got people trained overseas. We wanted to set up a test pilots school, but it wasn’t supported by the ‘powers that be’, so it didn’t happen,” he recounts.

“We developed a pretty awesome defence industrial machine pre-1994, a world leader, out of necessity,” he highlights. During the 15 or so years from the start of the 1980s to the middle of the 1990s, South Africa developed four major aircraft programmes that required flight testing. These were the Denel Cheetah, the Denel Oryx, the Denel Rooivalk and the Denel Ovid.

The Cheetah was a radical upgrading – in many respects a rebuild – of the Dassault Mirage III; the initial version, the two-seater Cheetah D, was unveiled in 1986 and the ultimate version, the Cheetah C, by 1992. Some 70 were produced, of all versions. The Denel Oryx medium utility helicopter is a hybrid of the Aérospatiale (now Airbus Helicopters) Puma and Super Puma helicopters and 51 were produced, with deliveries starting in 1989. The Denel Rooivalk attack helicopter was a completely new airframe, designed from scratch – the programme involved two test beds (based on existing helicopters), one prototype and three preproduction aircraft, followed by 12 production aircraft, delivery of which started in 1998. The Ovid was a composite airframe technology demonstrator, a tandem two-seater, single-turboprop engine aircraft also known as the ACE (All Composite Evaluator); only one was ever completed (two were planned). It first flew in 1991, but was sadly lost in an accident in 1995. In addition, there were many modifications to the SAAF’s existing aircraft, which also had to be flight tested.

“We developed huge flight test experience,” notes Muller. “At the peak of flight test activity in South Africa, the SAAF probably had about nine or ten test pilots, both rotary- and fixed-wing, and seven or eight flight test engineers.” Denel also had its own flight test crews – about three or four test pilots and three or four flight test engineers, organised into teams of one test pilot and one flight test engineer each. “Test flying had a lot of support from the SAAF. Flight test requires specially-instrumented aircraft, which the SAAF had to supply.”

Losing Altitude

Following the establishment of full democracy in 1994, South Africa was able to send pilots openly to the leading overseas military test pilots schools. “Our philosophy became to train one team every two years, fixed-wing and rotary- wing alternating,” he says. “And we sent them to different schools, to get the maximum exposure and benchmarking. We also did some work with the Russians – for example, fitting Russian engines into Dassault Mirage F1 fighters (work done by private-sector company Aerosud), so we also gained insight into Russian design, operating and maintenance philosophies.”

But the advent of peace and democracy also saw major cuts in the country’s defence budgets. Programmes were slowed down, when not cancelled outright. Proposed new programmes were delayed, if not terminated. The need for flight test declined, but most certainly did not disappear. However, although the SAAF was able to maintain a strong flight test capability until the early 2000s, continuing low defence spending led to an increasingly cash-strapped air force to repeatedly de-prioritise flight test.

“Since the early 2000s, there has been a constant degradation,” he points out. “Today, the SAAF has less than a handful of test pilots – perhaps one rotary-wing and one fixed-wing, plus two or three, maximum, flight test engineers. The last time people were sent on a test pilot’s course was in 2008/9! And the availability of specially instrumented aircraft has also severely declined, due to budget cuts. Test pilots have to fly such aircraft to maintain their expertise. The SAAF has barely managed to hold on to its flight test expertise. This reflects wider problems in the air force. We’ve had to cut back and we’ve lost a lot of capabilities,” Muller says.

“The size of the flight test cake has reduced considerably,” observes CSIR contract R&D manager and former test pilot Major-General Des Barker SAAF (retired). “This has paralleled the decline in the local aerospace industry, where many small and medium-sized enterprises have disappeared. The local test pilot and flight test engineer corps has shrunk so much that we’re now almost at the point of no return.”

Denel still has its own complement of test pilots and flight test engineers, but does not train new ones. There are a couple of private-sector companies employing test pilots for their own aircraft programmes (see below). And there is the private-sector Test Flight Academy of South Africa (TFASA), which trains overseas test pilots and flight test engineers, mainly from China, but which also does some certification test flying for small local companies and some companies in China. But the total number of active Class I test pilots in South Africa is now only about eleven fixed- and rotary-wing pilots, while the number of flight test engineers is down to twelve.

“There is no money for training overseas – it’s the foreign currency exchange rate that is the killer; the alternative would be to train locally, but training test pilots and flight test engineers is very expensive,” he notes. “It would cost about R10-million to train one test pilot and about R8-million to train a flight test engineer.”

But loss of national flight test capability and expertise would significantly damage both the local aerospace industry and the SAAF. “Flight testing is really quality assurance for products being developed or acquired,” he explains. “In terms of acquiring aircraft for our air force, we must have SAAF test pilots, committed to the needs of the service, to provide independent evaluation of those aircraft and to check the claims made by the manufacturers in their brochures.”

Taking Wing

As far as flight test is concerned, Denel remains active. While it is not currently developing complete aircraft designs (although it has serious proposals, such as the Small African Regional Aircraft, or SARA, and the Rooivalk Mark [Mk] 2), it continues to develop new weapons and systems that have to be integrated on to aircraft, processes that require test flights. However, there are also smaller companies in South Africa that have recently developed, or are developing, aircraft, although most of these fall within the glider, microlight, sports and light aircraft cate- gories. All these small aircraft still had to, or will have to, undergo flight test, possibly contracting this function out to specialist companies such as TFASA.

There are, however, a couple of larger projects under way, requiring in-house flight testing. One of these is the Paramount Ahrlac (Advanced High Performance Reconnaissance Light Aircraft), which was the subject of the cover story of the Engineering News of October 7, 2016. Another is a civilian project, the Falcon Air Falcon 402.

The Falcon 402 is a radical redesign and a complete rebuild of the twin-piston-engine Cessna 402, of which 1 535 were produced from 1966 to 1985 (including the initial 401 model). The Falcon 402 replaces the two Continental engines of the Cessna 402 with a single Walter Diemech M601D turboprop. This obviously involves major changes to the wings and the fuselage. The wing-mounted piston engines and nacelles are removed, the wing structure is reinforced and new fuel tanks are fitted. The nose forward of the cockpit is removed, a new engine cradle is fitted in its place and the new engine stalled and a new throttle quadrant is fitted. The aircraft is fitted with a glass (digital) cockpit and its interior is upgraded. The designer is Hendrik Venter, owner and CEO of the company and the end result looks like a totally new and very different aircraft, which is effectively what it is.

“The Falcon 402 is not the fastest single- engine turboprop around,” notes Falcon 402 project engineer David Toma. “However, the Falcon 402 is cheaper to acquire, cheaper to run, cheaper to maintain and can carry its own weight in luggage plus fuel, legally, and continue to fly 800 nautical miles with a 45 minute fuel reserve. The Falcon 402 offers over 1.5 t of useful load – that is, full fuel plus eight 100 kg-weight persons on board, each carrying 13 kg of luggage.” The aircraft can also operate in cargo configuration, or club seat configuration with six people.

Four Falcon 402s are now flying. The fifth will take to the air before the end of the year and the sixth early next year. Build numbers have been assigned for aircraft 7, 8, 9 and 10, which are in the planning stage. “Currently, the flying Falcon 402s are classified as non-Type Certified aircraft, a category which includes veteran and vintage aircraft, kit-built aircraft and so on, so we need to get separate approval for each aircraft,” explains Toma. “What we want is, with aircraft number 10, to achieve Type Approval, which would then cover all subsequent 402s that we build. Once we get Type Approval, we will move on to a more formal production-line manufacturing process. This will be followed by Type Certification of the Falcon 402. Our longer-term plan is to abandon the Cessna 402 airframe and adopt an all-composite airframe, and then seek Federal Aviation Administration (FAA) approval in the US.”

The Falcon 402 programme currently involves the test flying of each aircraft as it is finished, in order to show its compliance with the rele- vant South African Civil Aviation Authority (SACAA) regulations as well as relevant sections of FAA regulations. The data from these flights will also contribute to the aircraft’s type certification programme. The test programme includes ground structural tests of the rebuilt wing and new engine cradle.

The relatively simple (in comparison to a jet fighter or civil airliner) Falcon 402 programme gives an idea of what flight test involves. Two test pilots are involved, both ex-SAAF – Class I test pilot Tony Smit and Class II test pilot Chris Erasmus. Toma operates as the flight engineer. The technical support team is headed by Venter, who is a Recreation Aviation Administration South Africa-approved person. The flight test programme is overseen by a Safety Review Board, composed of the two test pilots, Venter and Toma. “Each flight is planned and a flight test card is prepared prior to the test flight,” elucidates Toma. “A hazard analysis is conducted for each flight and the appropriate steps taken to minimise risk through either procedure or actions.”

All aspects of the aircraft’s performance are examined in the flight test programme. Before the first flight, there are engine ground runs, ground handling tests, low speed and then high speed taxiing tests and a final inspection before the maiden flight. Then follows the first flight, with initial handling checks. The airspeed indicator is calibrated. In subsequent test flights, engine restarting in flight is demonstrated; static longitudinal, directional and lateral stability is checked, as is dynamic stability. Wings level stalls, turning and accelerated stalls are demonstrated. General flying characteristics are examined. Climb performance and gliding performance are checked. And the all-round controllability of the aircraft is demonstrated. (These tests are not necessarily in the order written.)

But the current rather parlous state of flight test in South Africa today is posing a problem for the Falcon programme. “The SACAA doesn’t have its own flight test department, which makes local [civil] type certification difficult,” points out Toma. “By not having its own flight test department, the SACAA has to depend on external flight testing companies for the evaluation of the aircraft. Such flight testing companies at times are the same companies that did the initial test flying anyway, owing to the small pool of test pilots in South Africa.” Falcon Air may have to seek type certification abroad, in a country whose approvals are accepted by the SACAA. But that would be much more expensive than doing it locally.

Conclusion

Test flying is essential to the future health of the local aerospace industry and of the SAAF. What should be done to ensure the maintenance of this very high-end skill in the country? “We need a suitable national aerospace project, such as the SARA or the Rooivalk Mk 2, and drive it forward. That will create the space for the current, experienced, aeronautical engineers, flight test engineers, test pilots and their ground-based supporting specialists, to pass on their expertise to the next generation,” argues Barker. “If that doesn’t happen, this expertise will most certainly be lost. We’re a relatively small country, yet we have several centres of flight test expertise. It is prudent to ask: What are we doing with such duplication? As a country, we need one national effort. We’re really at the crossroads. Most importantly, we need the political will to restore the situation, thereby enabling the South African aerospace industry to fulfil its rightful role as a player in the world’s aerospace development and testing market.”