Embraer has a long tradition of identifying – and succeeding in – unattended market niches. Over the years, they have done this with regional turboprops and jets, turboprop trainers and counter-insurgency aircraft, airborne early warning aircraft, light business jets and now the mid-range military transport segment, where the Lockheed C-130 Hercules has reigned supreme for more than 60 years.
The Brazilian transport programme started off in 2007 as the C-390, a simpler, low-tailed Embraer E-190 derivative with a new transport fuselage. Significantly transformed, the enlarged KC390 was relaunched from scratch and has now cleared two key milestones in a row: the first prototype roll-out ceremony last December, and first flight in February. The next stage to be crossed will be the full start of the flight-testing programme.
“The KC-390 programme has been developing on schedule, and the delay to first flight from the end of December to 3 February was only due to minor issues such as the two to three days needed to switch a faulty component in the prototype,” explains Col Sérgio Henrique da Silva Carneiro, KC-390 programme manager in the Brazilian air force’s combat aircraft co-ordinating committee (COPAC).
“There was no rush to get to the first flight, which was more than just a take-off and landing to prove the plane can fly. It was much more complex than that: a 1h 19min test flight in full telemetry gear.”
After that first – and only, as this article went to press – flight the prototype was returned to the manufacturing hall to receive some pending components and systems needed for the start of the complete flight certification schedule.
The first of two protoypes made its maiden flight in February
Embraer
“That flight was done with a reduced flight envelope, but it was enough to allow us to say that the aircraft’s behaviour so far is either as planned or better,” says Embraer’s vice-president and KC-390 programme director, Paulo Gastão Silva.
“Low-speed flight stability, for instance, turned out better than we had aimed to achieve. The close matching of the observed flight characteristics to what we planned in our digital model is a very good sign that we may run into fewer surprises down the road.
The second KC-390 prototype is scheduled to fly by mid-2015 – soon after the first returns to flight. They are followed in the production line by two complete airframes to be used for ground-based testing. Another two partial airframe structures will also be used, to speed up the certification process.
Immediately after these four test airframes, the first production examples for the Brazilian air force will start rolling off the expanded Gavião Peixoto manufacturing plant. Manufacture of the first production-standard aircraft is under way, with their long-lead items already contracted to Embraer suppliers.
Giant-sized genesis
“The Brazilian air force (FAB) and Embraer always had a clear notion of the size of the challenges that come … with large technological leaps forward,” says Carneiro. “But we also know there tends to be greater learning for industry in defence programs than in civilian ones.
“The KC-390 programme represents a step up in capability for both Embraer and its suppliers. Leaps like these are the result of well-managed defence programmes, bringing greatly positive results for the Brazilian aeronautical industry. Military requirements are continuously evolving, since this is the ‘cutting edge’.”
When the original C-390 concept was conceived, the designers knew it already brought with it a number of new challenges for Embraer. The effort and risk of creating a totally new fuselage with an integrated rear cargo ramp and other new items was then offset by the use as much as possible of tried and tested engines, systems and equipment inherited from the very successful civilian E-Jet family.
A new extended wingtip would be needed, as well as a new wing stub structure connected to the centre fuselage structure, which transformed the original shorter E-Jet wing, moving it from its original low-wing dihedral into a totally new high-wing anhedral installation. This was Embraer’s first high-wing design.
The designers felt the C-390 was both viable and technically feasible as a military transport, but it was clear it would be an aircraft of a lesser category in terms of loads and weights, in line with the French-German C-160 Transall rather than the market’s yardstick, the C-130J Hercules.
At this stage, Embraer was able to obtain assistance from the Brazilian air force, “an experienced service who deeply understood the military transport mission and is competent in writing detailed military requirement lists needed to properly evaluate the new concept”, says Gastão Silva.
The Brazilian air force already had a formal process for that purpose, so in an exploratory manner it contributed by writing an operational requirement, followed by a technical requirement, for the C-390 concept. This helped Embraer understand that its original concept answered the needs of only a part of the existing C-130 global client market. But the largest slice of that pie would be beyond its means to capture.
The logistical and industrial technical requirements were written by an air force working group. With a total of some 1,500 lines, the resulting requirement book revealed beyond doubt that the C-390 concept did not meet the service’s minimal performance needs. Intended as the base for the development contract of the new aircraft, the requirements document instead became its death knell.
Surprisingly, Embraer management opted for the longer road, starting again from scratch and creating a complete new aircraft. According to Gastão Silva, in the end Embraer’s development effort with the new KC-390 would amount to 130% that of the whole E-Jet family.
The C-390 concept’s size was inadequate. To be a commercial success in the military market it would have to be of equal or larger size than the Hercules. Embraer studies showed that while the company’s civilian E-190 had a wing area of 92m2 (990ft2) and the C-390 concept would have had a wing area of 108m2, the newly designed KC-390 ended up with a much larger wing area of no less than 140m2.
Off-the-shelf
The selection of a civilian-proven engine helped to reduce the flight-testing workload, but the International Aero Engines V2500-E5 variant used on the KC-390 has been adapted to better suit it to its unique military mission.
The same applies to the Rockwell Collins Pro Line Fusion cockpit displays. While BAE Systems was hired to supply the primary flight commands, all the aircraft’s fly-by-wire control laws were written in-house by Embraer.
“The KC-390 brought with it a number of good surprises for us,” Carneiro says. “We made flying this plane a very automated process, beyond the automatic pilot computers, protecting the plane from pilot inputs that might push it outside its flight envelope.”
Regarding export opportunities, Gastão Silva says that “creating a 100% ITAR [International Traffic in Arms Regulations]-free product would have been an pointless goal, because even Brazilian-developed and -sourced items have export control rules that apply to them. Every government whose companies produce military solutions and products – not just the USA – tends to reserve the right to control where that technology is going to end up.”
He adds: “Even some civilian-used products embed ITAR components such as the FADEC digital engine controls of the IAE V2500 engines” developed to power civilian airliners, but eventually used in the KC-390.
Another risk mitigation initiative involved the substantial use of simulation and Computational Fluid Dynamics (CFD) studies, as well as ground rig-based testing. A total of eight windtunnel testing campaigns were undertaken, two of which were for the original C-390 concept. These campaigns were used to evaluate several trade-off issues such as the wing-tip options.
Gastão Silva explains that “depending on the client air force’s average operational flight profiles, it might be an advantage to fit a winglet or another shaped wing-tip extension to its particular KC-390s. The wing structure, for instance, is designed and built to allow for simple alterations like that to be performed in the future.”
The test flight lasted 1h 19min with a full telemetry system
Embraer
Another area where the early windtunnel tests proved helpful was in the determination of the optimal engine pylon configuration. Gastão Silva mentions that the prototypes have silver-coloured engine pylons because of their hot running engine bleed air-driven internal components. At this temperature, any paint would be burnt away. To address FAB’s request for camouflaged pylons on its KC-390s, Embraer is currently searching the market for an adequate heat-resisting paint.
During its development process, the empty weight of the KC-390 has naturally grown, but so too has the engine power and aerodynamic efficiency of the design performance, so all the key performance items have been met by the aircraft flown by Embraer.
“FAB never specified an minimum empty weight parameter to Embraer in this programme,” COPAC president José Augusto Crepaldi says. “The KC-390 today has become capable of lifting 26t if this weight is concentrated in a limited area near the centre of gravity of the aircraft.”
International strategy
The KC-390 is a fully-fledged international partnership, with Argentinian, Portuguese and Czech flags showing up on the cockpit sides of the prototype at the roll-out ceremony. Besides these countries Embraer also reached out to Turkey, Chile, Colombia, South Africa and the United Arab Emirates as potential industrial partners.
Foreign involvement began at a ministry of defence level before progressing to air force commands and then reaching the aerospace industry. Chile and Colombia are still committed to the KC-390 program for 12 and six aircraft respectively. Chile was expected to join the KC-390 programme through manufacturer Enaer, but due to a change in government and the costs of the 2010 earthquake it eventually missed the industrial opportunity window.
NATO countries Portugal and the Czech Republic are seen as key in leveraging sales of the KC-390 to European air forces. These country’s industries also benefit from regional development programmes through low interest rates aimed at aerospace opportunities and industrial development. This financing will mostly be used for pre-manufacturing and series manufacturing non-recurring work. The contract signed by the industrial partners with Embraer covers both prototypes and series production work. “It is a win-win game” says Carneiro.
The KC-390 is expected to be composed of some 50% of Brazilian components by cost. “An aircraft is substantially different from oil rigs or even submarines” says Carneiro, referring to other large industrial transfer-of-technology programmes being developed in Brazil today.
Managing risk and cost
“Why does a beetle fly?” asks Gastão Silva. “Because he never went to aerodynamics class! We took the leap of faith of designing a type of aircraft we had never designed before because we didn’t know then how complicated it would be to design a brand-new, world-class, jet-powered tactical transport like the KC-390. We faced an enormous challenge in this programme – in reality it was not one but several specific challenges that had to be overcome.”
Embraer aircraft development programmes use a technology readiness index to determine the degree of risk represented by each possible type of innovation to be adopted in the new model. By sticking to the most mature technologies, the company cuts the overall programme risk.
A risk management plan was developed identifying the greatest risks, so during planning the search for their solution was intensified. One of these risk-reducing measures was the hiring during the initial phases of foreign consultants to assist on some of the more complicated parts of the new aircraft, such as the configuration of the rear cargo door and rear pressure bulkhead. This item’s complexity is derived from multiple independent aspects such as fuselage pressurisation, resistance to operations from unprepared airstrips and the need to guarantee an unobstructed cargo “launch corridor” in the rear of the cargo compartment.
This aims to reduce the risk of air-launched cargo pallets rubbing against the sides or eventually getting stuck in the rear door, potentially causing a fatal accident. The “unobstructed corridor” was the main reason for the adoption of the “T” tail configuration and for the raising and re-contouring of the rear fuselage. Without it the height of air-launched pallets would be more limited, which would have an impact on the KC-390’s operational flexibility.
Another key area identified by the Brazilian company was the complex automated cargo handling system/aerial delivery system (CHS/ADS) needed to allow easy movement of containers/pallets into and out of the airplane. The KC-390’s cargo compartment floor tiles can be easily flipped around, exposing or hiding rollers and tie-down rings of different strength levels to be used from light pallet loads all the way to heavy armoured vehicles.
The aircraft exited its construction hangar for a roll-out ceremony on 21 October 2014
Embraer
The ADS element of the system specifically refers to the safe and fast in-flight launch of military cargo. Civilian cargo transport operators are totally unfamiliar with this area, where restraints have to pop open at the right moment or where extractor parachute cords in an emergency might have to be sheared to preserve the safety of the crew on a mission. A jammed cargo load well to the rear of the aircraft’s centre of gravity is a critical – if not deadly – situation.
Prototyping strategy
The decision to use only two prototypes, according to Gastão Silva, was mainly due to the limits of development funding from the air force. “This number is fully compatible with the KC-390 program’s allotted development budget. A smaller number of prototypes demands from Embraer a much better flight-testing and certification campaign plan”.
Regarding the number of prototypes, Carneiro argues that “based on Embraer’s experience developing new aircraft, the use of risk-mapping strategies, the extensive use of simulations and the selection of mature technologies, we became confident that this would work well. Both prototypes are expected to be flown in tests for at least two to three years. When the first production aircraft are delivered, they will also be used to conclude the military type certification phase side by side with the prototypes”.
Carneiro also says a lot of work has been focused during development on ensuring the through-life cost of the KC-390 would be the lowest possible. The KC-390 programme contract has transfer-of-technology clauses for eight “strategic” subsystems, including engines, flight controls, avionics, landing gear, self-defence systems, cargo handling systems and mission systems. These transfer-of-technology offsets can vary from the local manufacture of a certain system or equipment all the way to a technical course COPAC and Brazilian industry believe will add value to the local industrial capabilities.
Manufacturing the giant
A new 30,000m2 final assembly hangar was built in Gavião Peixoto to accommodate the KC-390 line. The L-shaped hangar hosts five assembly stations. Built at another hangar, the fully assembled fuselage enters through a door at the bottom of the “L” shape, progressing upwards. In the horizontal part of the “L”, both half-wing assemblies are mated to each other before being installed over the fuselage. Also here, the horizontal stabilisers are assembled on top of the vertical tail before the completed structure is bolted to the fuselage. All components enter the final assembly hall fully painted.
Some of the KC-390’s major fuselage components come from the Embraer aerostructures plant located at Botucatu, 175km (109 miles) away from Gavião Peixoto. Some subassemblies are built locally at Gavião Peixoto and others come from the company’s headquarters at São José dos Campos. Other parts come from the new highly automated Embraer plant in Évora, and from OGMA, both located in Portugal. OGMA is responsible for the complete central fuselage assembly delivered in the shape of “super panels”. All foreign-built components are to arrive by ship, to be driven to Gavião Peixoto.
When the production reaches its full rate, around 1,060 jobs will have been either created or preserved at Embraer, while another 1,500 jobs were created in the engineering design group just for this programme. The marketing effort has run continuously from before the programme’s launch at the LAAD 2007 show, but international sales activity only began at the beginning of 2014. With the KC-390’s configuration frozen then, Embraer could finally make firm commitments regarding the plane’s performance, prices and delivery schedules. There are several active sales campaigns underway around the world today.
The future
Unveiling part of the company’s marketing plans, Gastão Silva says the current configuration is just the first of a family of aircraft in an overall product roadmap. “We foresee a market need for a stretched variant of the basic military transport for those clients whose cargoes have a greater density variation,” he says.
The current KC-390 cargo hold is already larger than the standard C-130’s, holding 7 pallets instead of 6, while its stretched variant will hold 9 pallets, one more than the C-130J-30. Troop transport is one of those missions that is better suited to a stretched airframe.
Source: FlightGlobal.com
