First public test flight of Airbus electric 2-seat E-Fan aircraft at E-Aircraft Day; precursor to 4-seat extended range version
|The successful first public flight of the electric E-Fan experimental aircraft took place during the E-Aircraft Day in Bordeaux. Click to enlarge.|
The Airbus Group’s electric E-Fan experimental aircraft made its first public test flight at E-Aircraft Day in Bordeaux, France. The electric E-Fan training aircraft is an innovative technology experimental demonstrator based on an all-composite construction.
Airbus Group plans to further develop the E-Fan technology demonstrator and to produce and market two versions of the aircraft by a subsidiary named VoltAir. The two-seater version E-Fan 2.0 will be a fully electric training aircraft powered only by batteries. The four-seater version E-Fan 4.0 will be a training and general aviation aircraft which will also have a combustion engine within the fuselage to provide an extended range or endurance.
First presented in the static parc at the Paris Air Show in 2013 (earlier post), the two-seat E-Fan features two electric motors with combined power of 60 kW, each driving a ducted, variable pitch fan. Total static engine thrust is about 1.5 kN, with the energy being provided by two battery packs located in the wings. The length of the aircraft is 6.7 meters with a wingspan of 9.5 meters.
|The all-electric E-Fan training aircraft. Click to enlarge.|
The duct increases the static thrust, it reduces the perceived noise and improves safety on the ground. The E-Fan is the first electric aircraft featuring ducted fans to reduce noise and increase safety. With the engines located close to the center-line of the aircraft, the E-Fan also has very good controllability in single-engine flight.
Another innovation of the E-Fan is its landing gear, which consists of two electrically-actuated retractable wheels positioned fore and aft under the fuselage, plus two small wheels under the wings. The aft main wheel is driven by a 6 kW electric motor, providing power for taxiing and acceleration up to 60 km/h during take-off, reducing overall electrical power consumption in day-to-day operation. The maneuvering of the aircraft on the ground and the initial acceleration on take-off without the main engines can so be done completely silently.
To guarantee a simple handling of the electrically powered engines and systems, the E-Fan is equipped with an E-FADEC energy management system.
As a first for an electrically powered aircraft, the E-Fan also features a pyrotechnically deployed airframe parachute rescue system.
|A five-minute view of design, assembly and first flight on 11 March 2014.|
The E-Fan’s motors are powered by a series of 250V Lithium-ion polymer battery packs, comprising 120 40Ah, 4V cells made by KOKAM. The batteries are housed within the inboard part of the wings outside the cockpit, and provided with venting and passive cooling. Because of timing and availability constraints, off-the-shelf Lithium polymer batteries are used in the technology demonstrator, giving an endurance of between 45 minutes and 1 hour. New batteries with a higher energy density will be installed later on, which will increase the endurance to up to 1 hour + 15 minutes reserve.
The batteries can be recharged in one hour, or they can be rapidly replaced by means of a quick-change system (not yet available on the demonstrator aircraft). An on-board 24 Volt electrical network supplies the avionics and the radios via a converter. A backup battery is provided for emergency landing purposes.
Take-off speed is 100 km/h (54 knots); cruising speed is 160 km/h (86 knots); maximum speed is 220 km/h (119 knots).
|Plan view and cross-sections of the wing show the E-Fan’s battery installation. Click to enlarge.|
Airbus sees the two-seat E-Fan as particularly suited for short missions such as basic pilot training, glider towing and aerobatics, with a flight endurance of one hour for pilot training and 30 minutes for aerobatics. E-Fan can bring significant benefits in terms of cost per flight hour in the general aviation domain, Airbus suggests.
Accordingly, Airbus Group and its partners are aiming to perform research and development to construct a series version of the E-Fan and propose an industrial plan for a production facility close to Bordeaux Airport. Airbus Group’s research efforts support the environmental protection goals of the European Commission, as outlined in its “Flightpath 2050” program.