The Silent 2 Electro
with its nose-mounted electric propulsion system constructed
specifically for the Silent is the most modern and environmentally
conscious design capable of satisfying the needs of ever increasing
The electric motor installed in the nose of the glider with folding propeller blades is aerodynamically
clean and has no additional drag during climbing or cruising flight.
The drag-reduction offered by the retractable
landing gear, vertical-design winglets, and variable-position
horizontal stabilizer, further expand the glide performance
Electric-powered flight does not
necessarily require the steady climbing flight typical of self-launch
gliders as the aerodynamically efficient nose-mounted propulsion system
allows sustained level flight at cruise speeds with minimal energy
A pair of lithium polymer (LiPo)
battery packs with a combined capacity of 4.3 kWh provides power. The
two battery packs, each weighing 15.5 kg (34.2 lbs), are positioned as
close to the center of gravity as possible. They are readily accessible
and removable via an access panel on the upper surface of the fuselage.
The batteries are transportable allowing them to be charged at any location, not just on board the sailplane.
Unlike NiCd or lead-acid batteries, LiPo batteries experience
negligible loss of charge (typically 1% per month) when stored at
The usual batteries needed to power
glider avionics can be eliminated as the LiPo propulsion batteries have
enough extra capacity for all other on-board power requirements. The
lifespan of the batteries is estimated to be approximately 1,500 cycles
to full discharge, after which the batteries are still capable of
holding 70% to 80% of a full charge.
Recharging is performed with a
1,200 W external charger which includes a Battery Management System
(BMS) designed specifically to balance the charging of LiPo batteries.
During charging the BMS controls the voltage to the various cells that
make up the battery packs so that their voltages are all within 0.02
The class-leading Silent 2 Electro is a
high-performance light self-launching sailplane for recreational
and sport flying.
- Motor with smaller size, lighter weight,
higher power output, and greater reliability when compared with any
internal combustion engine
Significant reduction in noise; the use of a radio headset is unnecessary during powered flight.
Extremely clean due to elimination of fuel, oil, exhaust fumes, etc.
Elimination of flammable fuel on board
Secure and instant start-up; the motor requires no warm-up prior to application of full power
- Almost complete absence of vibration; the only moving parts are the propeller and the rotor
- Motor maintenance is essentially unnecessary
- The nose-mounted motor is on the fuselage
center-line and thus has no forward pitching moment to create take-off
difficulties as is typical of pylon mounted propellers
- No loss of motor power as a function of altitude; performance is unvaried with respect to atmospheric conditions
- Motor use is extremely simple; no raising of a pylon, simply turn on the master and apply power
- Complete absence of aerodynamic resistance (engine pylon, etc.) and consequently better flight performance
- Mechanical simplicity and uncomplicated use of the entire system, when compared to solutions with a retractable powerplant
- No change to the aerodynamics when using the motor
- No change to the center of gravity when changing between powered and unpowered flight.
- Propeller located in front of the cockpit and safely visible to the pilot at all times
- Complete availability of extra electric energy for even the most well-equipped instrument panel
The wings have an elliptical planform, vertical
design winglets, and a span of 13.2 meters. The wing structure
includes extensive use of carbon fiber, both in the sandwich
skins and in the tapered
I-beam wing spar which uses pultruded carbon rods for the
spar caps. The wing geometry is unique in that it varies non-linearly
from the root to the tip, both in overall planform shape and
in wing section profile. The flaperons stretch for 11.0 meters
of the full wingspan and their range of motion varies from
positive landing L, to +1 for thermalling, to 0,
-1, and S reflex positions for cruising.
The sailplane is trimmed in pitch via
an innovative variable-position horizontal stabilizer. The
stabilizer position is governed by the flaperon setting: the
five settings of the flap control produce corresponding changes
to the stabilizer incidence, thus defining the trim airspeed
in relation to the flap requirements. The conventional elevator
remains in trail, minimizing trim drag.
The ingenious trim system,
the elliptical planform geometry of the tailplane, the vertical
design winglets, and the retractable landing gear all combine
to yield improved performance over a wide range of airspeeds.
< 65 km/h (40 mph)
||150 km/h (93 mph)
220 km/h (137 mph)
40 at 90 km/h (56 mph)
0.60 m/s (118 ft/min) at 85 km/h (53 mph)
|Takeoff distance (asphalt):
~140 m (~460 ft)
|Takeoff distance (grass):
~160 m (~525 ft)
~100 m (330 ft)
|Powered climb rate:
~2.0 m/s (~400 ft/min)
Glider Technical Data
||13.2 m (43,3 ft)
6.35 m (20.8 ft)
1.25 m (4.1 ft)
8.9 m2 (95.8 ft2)
Elliptical (with winglets)
IMD 050 (16%)
205 kg (452 lbs)
105 kg (231.5 lbs)
|Structural max. takeoff / landing weight:
315 kg (694.5 (lbs)
+5.3 g / -2.65 g
(at 150 km/h at 315 kg)
+4.0 g / -1.5
(at 220 km/h at 315 kg)
loading at 300 kg (661 lbs):
L +1 0 -1 S
|Conventional air brakes
|Fully automatic control connections
|Retractable landing gear
Brushless DC Electric Motor Technical Data
6.5 kg (14.3 lbs)
1.00 m (39.4 in)
|Weight of batteries:
31.0 kg (68.3 lbs)
|Standard charging time:
approx. 150 min at 220V
Carbon and glass fiber COMPOSITE FUSELAGE
with epoxy resin.
Composite SANDWICH WING SKINS, pultruded
HORIZONTAL TAILPLANE of elliptical planform.
Variable incidence stabilizer and conventional elevator.
T-TAIL and large rudder surface.
Generous 11M FLAPERONS; the flap range is
L + 1 0 - 1 S.
Fully AUTOMATIC CONTROL CONNECTIONS for wings,
fuselage and horizontal tailplane.
Removable VERTICAL-DESIGN WINGLETS.
One piece HINGED TIP-UP CANOPY, side window
with air vent.
Main wheel BRAKE activated via air-brake
control aft travel. AUTOMATIC TRIM connected
to the flap lever to get the ideal trimming.
Polymer WING-TIP WHEELS with fairing, for
taxiing on asphalt or grass.
RETRACTABLE main wheel, 4.00x4” 6-ply
tire with tube.
Fixed TAIL WHEEL (Steerable with fairing as option).
In-flight ADJUSTABLE RUDDER pedals.
Central INSTRUMENT POD and engine control.
BASIC FLIGHT INSTRUMENTS: 80mm altimeter,
57mm air-speed indicator, compass, Winter 57mm variometer,
total energy probe (Althaus).
4-POINT HARNESS with quick-release.
Cockpit side POCKET, HEAD REST, SEAT-PAN
LINER WITH CUSHION, TOOL POUCH.
installed in the nose of the glider
Composite FOLDING PROPELLER blades
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