TOP TECH AV DEVELOPMENT 2015
Airbus Group flies E-Fan and will build, certify and sell it
All-electric technology demonstrator made historic crossing of the English Channel. E-Fan 2.0 will be side-by-side LSA. Coming is 4-place GA E-Fan.
A technology demonstrator suit- able for production
E-Fan's modern connected cockpit will also make learning to fly more intuitive, while the full authority digital controls (e-FADEC) will handle the aircraft's electrical power functions.
The next step was the development of the E-Fan technology demonstrator. "Apart from the technology, another innovative approach was to reach out within the wider Airbus Group and partners and team up with small and medium-sized enterprises. With this new idea, it took 18 months to develop the prototype ahead of its 1st flight in Bordeaux in March 2014," relates Müller-Wiesner.
Out of its learning from the initial iteration of the E-Fan Technology demonstrator, Airbus Group has further developed the technology demonstrator to reduce weight by 20 kilograms and improve battery capacity by more than 60% within a year's time.
Müller-Wiesner adds, "All these developments allowed the 1st English Channel crossing ever with an electrical aircraft starting by its own and landing by its own on July 10, 2015.
With respect to the Channel crossing, we also learned a lot about the verification of the whole electrical system from a safety point of view. For example, we learned what to do in case of engine shutdown, with either of the 2 engines, by means of simulations."
Müller-Wiesner continues, "What could be the role of a small aircraft within a long-range vision? Do we stay with a demonstrator or do we go for a low certification level early into the market? We did market studies and found out that, especially among private pilots and pilot schools, there is indeed a market for a GA aircraft that has a flight time of around 1 hour and 30 minutes (including reserves) if it is less costly and less noisy than a normal training airplane with a single engine.
There is also an interest from the basic flight training market because our E-Fan requires less maintenance and has lower operating costs, as there is no need for fuel. In a piston engine there are many parts that need to be maintained and changed, but this is not the case with an electric engine. The existence of a market in Europe and the US, as well as a wider glob- al market, was confirmed by professionals during our research stage."
Airbus Group consequently teamed up with its other partners and made a proposal to the French Government for fitting the E-Fan aircraft development project in one of the French Government's innovation road maps. "The support was approved by the French Ministry of Economics.
As part of this program, planning for the industrial development of the E-Fan, we decided to certify the E-Fan 2.0 under CS-LSA (EASA Certification Specifications for Light Sport Aircraft) as a 2-seat aircraft. For this purpose we started a company called VoltAir SAS, which is 100% owned by Airbus Group but can act more flexibly as a small or medium-sized enterprise," explains Müller-Wiesner.
There will be 2 versions in the marketplace
Airbus Group's E-Fan technology demonstrator has been modified to reduce its weight by 20 kilograms. It features retractable landing gear and an optimized battery capacity, improved by more than 60% in less than a year.
Airbus Group is planning entry to market for its E-Fan 2.0 all-electric, 2-seat aircraft in late 2017. Curiously enough, Airbus Group's E-Fan team says it is already receiving requests to buy the aircraft even though the design has not yet been finalized.
"With respect to the architecture, when compared to the E-Fan technology demonstrator, the E-Fan 2.0 is not a tandem but a side-by-side pilot seat configuration. This has been done in order to match the needs of pilot training, which is better delivered to the student in a side-by-side seat configuration.
After the E-Fan 2.0, the next step will be the E-Fan 4.0, a 4-seat aircraft with hybrid propulsion. In addition to the electric motors, the E-Fan 4.0 will also be equipped with a combustion system that will recharge the batteries to directly power the electrical engines.
Airbus Group is currently working on the technology for charging stations with the capability to recharge the E-Fan batteries in 1 hour. "The plan is not just for the aircraft to receive a supply of electricity, but also to make possible a data exchange between the airplane, equipped with the connected cockpit, and the charging station in order to provide pilot schools with data such as the flightplan and the actual flight, as well as parameters of the electrical system," says Müller-Wiesner.
Indeed a key feature of the Airbus Group's connected cockpit concept for the E-Fan is the ability for an instructor and pilot to prepare their flightplan in advance on a tablet device for uploading to the aircraft. The tablet is plugged into the cockpit instrument panel and serves as the navigation and training display. After landing, data can be retrieved on the tablet, allowing the actual flight to be compared with the pre-planned scenario.
"Furthermore, in agreement with the customers and in a neutral way, we would aim to access the technical data coming in from the operations of the aircraft. All of this, of course, with utmost compliance with data security regulations," Müller-Wiesner adds.
Airbus Group is also looking at the possibility to actually change the batteries while the airplane is on the ground, but this has not been finally decided as yet.
When an aircraft development project goes for a high certification level, there is a need to compute calculations regarding engine reliability. And due to the relative novelty of electrical engines in aircraft applications, doubts may reasonably arise.
Müller-Wiesner, however, provides a reassuring perspective on the reliability of electrical engines. "If you compare an electrical engine with an internal combustion engine that has many moving parts (crankshafts, pistons, etc), it is obvious that an electrical engine has less moving parts, as well as lower operating temperatures. When investigations on engine reliability will be performed on the test bench in terms of such things as failures for thousands of hours, it is likely to expect that the reliability of an electrical engine will be in the same range or higher than a traditional engine's," says Müller-Wiesner.
Airbus Group already has figures as to how much their electric aircraft will cost, but it has not disclosed those figures yet because the company is still working on a service model that will sell not the airplane, per se, but the availability of the airplane in terms of flying hours for pilot school customers.
"The idea is that the total cost of ownership per flight hour will be at least 20% lower when compared to that of conventional aircraft."The airplane will also be available for full ownership. Personally I am convinced that smaller aviation clubs, in order to get rid of the capital expenditure, will prefer the service mod- el. Nevertheless we already have requests by private individuals who are keen on such technology," declares Müller-Wiesner.
Value added for bigger hybrid aircraft
"As an aircraft manufacturer, our main aim is not to produce small electrical aircraft on a wide scale," states Müller-Wiesner. "Our aim is rather to develop the technical working knowledge and experience at a low certification level with utmost compliance to all applicable safety regulations, on the behavior of the electrical propulsion unit, including the battery, the e-FADEC control system, the engine and so on, and to get data for our own research and development for bigger engines to power hybrid regional aircraft for up to 70 passengers—although there is no corporate decision yet to enter
the RJ market. The purpose of the E-Fan project is to develop the knowledge and technology to enable such a decision."
The E-Fan project is a clear example of how aviation enthusiasts who are committed to the sustainability of the aviation industry can lead the way for more efficient energy consumption and reduced emissions.
With the Airbus Group's proactiveness and its ability to draw and generate solid know-how, the expectation is that industry targets for reduced fuel consumption and emissions will be reached sooner rather than later with the experience that will come from E-Fan operations.
Mario Pierobon is a safety management consultant and content producer who is currently working on an airside safety research project.
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