The Airbus/Rolls-Royce/Siemens E-Fan X was a

hybrid electric aircraft A hybrid electric aircraft is an aircraft with a Hybrid electric vehicle, hybrid electric powertrain. As the energy density of lithium-ion batteries is much lower than aviation fuel, a hybrid electric powertrain may effectively increase flight rang ...

demonstrator being developed by a partnership of

Airbus Airbus SE ( ; ; ; ) is a Pan-European aerospace corporation. The company's primary business is the design and manufacturing of commercial aircraft but it also has separate Airbus Defence and Space, defence and space and Airbus Helicopters, he ...

Rolls-Royce plc Rolls-Royce Holdings plc is a British multinational aerospace and defence company incorporated in February 2011. The company owns Rolls-Royce, a business established in 1904 which today designs, manufactures and distributes power systems for ...

and

Siemens Siemens AG ( ) is a German multinational technology conglomerate. It is focused on industrial automation, building automation, rail transport and health technology. Siemens is the largest engineering company in Europe, and holds the positi ...

. Announced on 28 November 2017, it followed previous electric flight demonstrators towards

sustainable Sustainability is a social goal for people to co-exist on Earth over a long period of time. Definitions of this term are disputed and have varied with literature, context, and time. Sustainability usually has three dimensions (or pillars): env ...

transport for the

European Commission The European Commission (EC) is the primary Executive (government), executive arm of the European Union (EU). It operates as a cabinet government, with a number of European Commissioner, members of the Commission (directorial system, informall ...

’s Flightpath 2050 Vision. A

BAe 146 The British Aerospace 146 (also BAe 146) is a short-haul and regional airliner that was manufactured in the United Kingdom by British Aerospace, later part of BAE Systems. Production ran from 1983 until 2001. Avro International Aerospace manu ...

flying testbed was to have one of its four Lycoming ALF502 turbofans replaced by a Siemens

electric motor An electric motor is a machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a electromagnetic coil, wire winding to gene ...

, adapted by Rolls-Royce and powered by its AE2100 turboshaft, controlled and integrated by Airbus with a battery. In April 2020, the programme was cancelled during the

COVID-19 pandemic The COVID-19 pandemic (also known as the coronavirus pandemic and COVID pandemic), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), began with an disease outbreak, outbreak of COVID-19 in Wuhan, China, in December ...

Development

Announced on 28 November 2017 at the

Royal Aeronautical Society The Royal Aeronautical Society, also known as the RAeS, is a British multi-disciplinary professional institution dedicated to the global aerospace community. Founded in 1866, it is the oldest Aeronautics, aeronautical society in the world. Memb ...

in London, the E-Fan X was initially planned to fly in 2020. It follows previous electric flight demonstrators: Cri-cri, e-Genius, E-Star and the E-Fan 1.2. It will anticipate a safe, efficient, and cost-effective hybrid single-aisle airliner. Airbus and Siemens have collaborated since April 2016 on the E-Aircraft Systems House for electric propulsion components, including ground tests. It will help establish

certification Certification is part of testing, inspection and certification and the provision by an independent body of written assurance (a certificate) that the product, service or system in question meets specific requirements. It is the formal attestatio ...

requirements for electric aircraft. Existing technologies cannot achieve

’s Flightpath 2050 Vision for Aviation goals towards

transports: a reduction of by 75%, by 90% and noise by 65%; new technologies are needed including electrification.
AirbusRolls-RoyceSiemens
At the 2018 Farnborough Airshow,

Greg Clark Gregory David Clark (born 28 August 1967) is a British politician who served as Secretary of State for Business, Energy and Industrial Strategy from 2016 to 2019. He also was Secretary of State for Communities and Local Government from 2015 t ...

, Business and Energy Secretary, announced the UK Department for BEIS will commit a part of the £255 million invested to develop greener flight technologies. At the June 2019

Paris Air Show The Paris Air Show (, ''Salon du Bourget'') is a trade fair and air show held in odd years at Paris–Le Bourget Airport in France. Organized by the French aerospace industry's primary representative body, the ''Groupement des industries frança ...

, Rolls-Royce announced its acquisition of

' electric propulsion branch, to be completed in late 2019, employing 180 in Germany and Hungary. On 19 August 2019, the compact generator was run for the first time in Trondheim, Norway, before integration with an AE2100 turboprop from a Saab 2000 feeding the battery pack and a Siemens SP260D electric motor (with a 10 kW/kg power-to-weight ratio) replacing one Honeywell LF507 engine with a Rolls-Royce AE 3007 fan, through a 3,000 volts AC/DC distribution. By November 2019, the airframe (G-WEFX) had arrived at Cranfield to be modified; first flight was then planned for 2021. In April 2020, the programme was cancelled amid the COVID-19 pandemic.

Design

flying testbed will have one of its four

turbofan A turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft engine, aircraft propulsion. The word "turbofan" is a combination of references to the preceding generation engine technology of the turbojet and the add ...

s replaced by a

, with provisions to replace a second turbofan. Airbus will build the control architecture and integrate the systems, Rolls-Royce will adapt the Siemens motor and the fan to the existing

nacelle A nacelle ( ) is a streamlined container for aircraft parts such as Aircraft engine, engines, fuel or equipment. When attached entirely outside the airframe, it is sometimes called a pod, in which case it is attached with a Hardpoint#Pylon, pylo ...

, bring the

turboshaft A turboshaft engine is a form of gas turbine that is optimized to produce shaft horsepower rather than jet thrust. In concept, turboshaft engines are very similar to turbojets, with additional turbine expansion to extract heat energy from the ex ...

, generator and

power electronics Power electronics is the application of electronics to the control and conversion of electric power. The first high-power electronic devices were made using mercury-arc valves. In modern systems, the conversion is performed with semiconduct ...

and Siemens the electric motor and its power electronic control unit, the

inverter A power inverter, inverter, or invertor is a power electronic device or circuitry that changes direct current (DC) to alternating current (AC). The resulting AC frequency obtained depends on the particular device employed. Inverters do the op ...

, DC/DC converter and

power distribution Electric power distribution is the final stage in the delivery of electricity. Electricity is carried from the transmission system to individual consumers. Distribution substations connect to the transmission system and lower the transmission v ...

. High-power propulsion systems are challenged by thermal effects, electric thrust management,

altitude Altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum (geodesy), datum and a point or object. The exact definition and reference datum varies according to the context (e.g., aviation, geometr ...

and dynamic effects on electric systems and electromagnetic compatibility issues. An inboard Lycoming ALF502 is replaced with a same thrust Citation X/ ERJ-145 AE3007 nacelle, but with its core replaced with the electric motor and inverter and the C-130J's AE2100 turboshaft in the rear fuselage with its air inlet behind the wing – both using the

V-22 Osprey The Bell Boeing V-22 Osprey is an American multi-use, tiltrotor military transport aircraft, military transport and cargo aircraft with both vertical takeoff and landing (VTOL) and short takeoff and landing (STOL) capabilities. It is designed ...

tilt-rotor's Liberty T406 core. While Rolls-Royce is experienced in industrial and naval applications, the generator feeding a 3,000 V DC distribution through its AC/DC converter are firsts in aviation. Airbus supplies a , battery in the cargo holds, a 30 times step up from the E-Fan. The Siemens motor Power/Mass ratio will be higher than the of the 2017 Paris Air Show Extra 330 demonstrator. The motor and generator are not cryogenically cooled and not

superconducting Superconductivity is a set of physical properties observed in superconductors: materials where electrical resistance vanishes and magnetic fields are expelled from the material. Unlike an ordinary metallic conductor, whose resistance decreases g ...

for more than 15% of losses but ultimate efficiency is not a prime target. The Rolls generator is oil-cooled with

supercritical carbon dioxide Supercritical carbon dioxide (s) is a fluid state of carbon dioxide where it is held at or above its critical temperature and critical pressure. Carbon dioxide usually behaves as a gas in air at standard temperature and pressure (STP), or a ...

as the intermediary cooling fluid, building on Rolls-Royce LibertyWorks’ power system for the Aurora XV-24A LightningStrike: a high-speed

VTOL A vertical take-off and landing (VTOL) aircraft is one that can takeoff and landing, take off and land vertically without relying on a runway. This classification can include a variety of types of aircraft including helicopters as well as thrust- ...

aircraft scheduled to fly in 2018 with electric distributed propulsion using Rolls’ AE1107 turboshaft (with the same AE2100 core) driving three

Honeywell Honeywell International Inc. is an American publicly traded, multinational conglomerate corporation headquartered in Charlotte, North Carolina. It primarily operates in four areas of business: aerospace, building automation, industrial automa ...

generators. The nacelle outer mold line will be kept to maintain the BAe 146

airworthiness In aviation, airworthiness is the measure of an aircraft's suitability for Air safety, safe flight. Initial airworthiness is demonstrated by a certificate of airworthiness issued by the civil aviation authority in the state in which the aircraft ...

approval. A Siemens DC/AC converter power electronics will feed the SP2000 liquid cooled motor, eight times more powerful than the Extra 330E's Siemens SP260D, the most powerful motor flying now with for 50 kg (110 lb). The

electric machine Electricity is the set of physical phenomena associated with the presence and motion of matter possessing an electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by ...

s should attain a 10-times-higher

power-to-weight ratio Power-to-weight ratio (PWR, also called specific power, or power-to-mass ratio) is a calculation commonly applied to engines and mobile power sources to enable the comparison of one unit or design to another. Power-to-weight ratio is a measurement ...

. Pressurization, insulation and separation will avoid the corona effect: high altitude, high voltage arcing. Hybrid electric can offer improvements with present Battery Technologies : using them to boost power for takeoff and climb and electric-only descent would lower fuel burn per sector by double digits, and would reduce

noise Noise is sound, chiefly unwanted, unintentional, or harmful sound considered unpleasant, loud, or disruptive to mental or hearing faculties. From a physics standpoint, there is no distinction between noise and desired sound, as both are vibrat ...

and local atmospheric emissions.

References

External links

* * * * * * * * {{Airbus aircraft Airbus aircraft Hybrid electric aircraft Proposed aircraft Quadjets Turboshaft-powered aircraft High-wing aircraft

Development

Design

See also

References

External links