Retractable Electrical Propulsion System
Elon Musk turned the car industry on its head. Who would think a few years back that the most luxury sedan would leave a Porsche behind in a drag race… and do this in silence with style….
Battery driven vehicles took the world by storm, and the general aviation is slowly catching up. No fumes of fuel, no oil leaks, no vibration, no engine noise, no breaking belts, no starter button.. This all sounds extremely attractive… but where is the catch?
Clearly the energy density is not nearly as good as their petroleum counterpart and therefore battery installations are still heavy for the performance they offer, and they are not as yet well priced. The risk associated with battery fires is a reason for concern, and EASA is actively working on improved special conditions to ensure safe designs – don’t underestimate manufacturers headaches when it comes to certification of systems with large LiPo batteries.
Well-known aircraft engine producer, SOLO Aircraft Engines, was the major inspiration behind the retractable electrical propulsion system. SOLO used the JS3 fuselage to model their sustainer design in the “smallest possible modern fuselage”.
JS and SOLO studied the maximum performance of the system and realized self launching may just be possible. The concept of having not only a sustainer, but also a limited self-launcher with removable batteries is very exciting. To enable this performance need the battery capacity was increased to 9.4 kWh running at 400V and a larger, more efficient propeller was matched with the motor torque curves to minimize losses.
Electrical Propulsion System Option
► EMRAX 188 Motor generating 140 Nm thrust at maximum speed of 4,200 rpm
► Peak power: 4,200 rpm and around 30kW for 2.5 minutes
► 2 removal batteries weighing 22kg each
► Battery capacity of 9-10 kWh
► Pilot interface: One switch controls pylon extension and doors
► Motor extension and retraction using an electrical linear actuator with mechanical sequencing to close engine bay doors in extended and retracted positions
► Configuration: 6S4P
► Voltage: 270V-400V
► Nom. Capacity: 12Ah
► Nom. Energy: 4.2kWh
► Weight: 22kg
► Standalone BMS
► Internal Relay-Safe Handling
► Internal Current Sensor
► Internal Fuses
