Electric Self-Launch Sailplane FAI CLASS 13.5m
The SILENT 2 Electro is the only self-launching sailplane incorporating the Front Electric Self-Launcher/Sustainer (FES) in serial production. The aircraft is capable of both unassisted take-off and periods of powered flight – as may be necessary to sustain soaring flight.
The highly efficient 22kW brushless electric motor installed in the nose is powered from two purpose built rechargeable Lithium battery packs and drives a folding propeller.
The power chain is aerodynamically clean and operationally very simple compared to a retractable power plant. It is also effectively maintenance free.
A typical self-launch will require a ground run of about 100m on a hard runway (~120m on grass) and can be expected to consume about 20% of the available battery capacity, leaving about 40 minutes of power available for use as a sustainer. There is no forward pitch moment on take-off and the motor delivers the same performance regardless of altitude.
Two purpose built Lithium battery packs, with built-in Battery Management System and a combined capacity of 4.4kWh are located behind the cockpit; very close the centre of gravity. Weighing just over 15kg each they are easily removed for charging.
Designed for the new FAI 13.5m class, every component of the glider is built to the very highest standard and everything is incredibly light! All control linkages are automatic; rigging could not be easier!
With a maximum take of weight (MTOW) of 300kg (or 313,5 kg if equipped with the optional ballistic recovery system) and a stall speed of less than 65 kph (35 kts) the aircraft is de-regulated in terms of air worthiness in most countries.
The glider is trimmed in pitch via an innovative variable-position horizontal stabiliser. The incidence of the horizontal stabiliser is governed by the flaperon setting; the five settings of the flap control produce corresponding changes in the incidence of the stabiliser, thus defining the trim airspeed in relation to the flap setting while the conventional elevator minimizes trim drag.
Thanks to the near full span flaperons, the SILENT 2 Electro soars effortlessly, even in the lightest air yet penetrates well, while the highly innovative drive chain delivers clean and efficient power – at the turn of a knob. The aircraft is a delight fly!
Basic data of standard FES electric motor:
• Out runner BLDC brushless synchronous permanent magnet motor with electronically controlled commutation system 3 phase
• 20kW continuous power at 116V
• Up to 22kW for shorter time
• Rotor rink diameter 180mm
• Length 100mm
• Weight of motor is only 7,3 kg
• Efficiency up to 95%.
• Rotor position by hall sensors
• BLDC motors need special Controllers for their operation. Controller is mounted on a cooling rib on top of main wheel box, and is cooled by three ventilators.
To read the motor manual click here
There is only one switch to turn ON instrument and a knob with rotary encoder which acts as throttle and propeller brake. Press on throttle knob, have also some additional functions like message confirmation, etc.
FCU instrument was specifically developed for FES system in cooperation with leading producer of gliding instruments LXNAV, who is also producing it for LZ design.
To read FCU manual click here
After propeller is stopped by electronic braking, it is automatically positioned to horizontal position. The composite spinner has recesses for the middle section of propeller blades and a central hole for cockpit ventilation and for air cooling of the electric motor. The ventilation can be closed during soaring flight and must be opened when motor is running.
Pitot measurement point is on top of vertical stabilizer, and works fine also during powered flight.
Nose cone in your trailer needs to be slightly modified, so that is not pressing to the propeller blades.
To read propeller manual click here
Our latest GEN2 Battery packs have integrated BMS (Battery Management System) and RADSOK high power quick connectors!
Batteries are also used to supply power for all instrumentation on board through a DC/DC converter. No other battery onboard is required anymore.
Power consumption of all instrumentation is very small (5W to max about 30W) compared to the motor consumption at full power. So you will finally have enough power for your radio, flight computer, PDA and transponder.
If batteries are discharged during flight using the motor, they still have plenty of power for instrumentation. It is easy to take them out of the fuselage, for charging.
To read battery packs manual click here