The engine electrical system includes the ECU
(Engine Control Unit), limit switches, engine
display unit with engine master switch, engine
control and throttle
which are inter-connected via a wiring loom.
The ECU is a digital electronic unit that controls
receives inputs such as throttle setting, engine rpm
and EGT (Exhaust Gas Temperature) and controls the
fuel pump rate, fuel solenoids (open/closed/pulsing)
and glow-plug ignition. The ECU includes a memory
card that records a number of parameters such as
throttle setting, engine speed and EGT, and also
data points/records such as number of start-ups and
error log information.
Limit switches in the front of the engine box are
operated by a bell crank when the engine is fully
deployed and by a cam when the engine is fully
retracted. The ECU will not initiate the starting
sequence if it does not receive the signal from the
deployed limit switch.
If the deployed limit switch
fails while engine is running, the ECU will simply
cut the engine power and register an error on the
engine display (and the pilot can select to retract
the engine by switching to retract).
In the event of a limit switch failing
while the engine is being retracted or deployed so
that the engine reaches the physical stops, the ECU
will stop the engine and give a kinematic error on
the engine display.
Electrical power for the sustainer is provided by
Li-Fe batteries, replacing the standard sealed
lead-acid batteries and situated in the standard
battery compartments in the centre table.
Control & Display System
The pilot controls the engine
using the JDU (Jet Display Unit). The
throttle is controlled using the rotary
control on the instrument while engine
retract/extend/run is selected by a single
The engine has an automatic start-up sequence that
will start only once engine is fully deployed.
Throttle control will only be given to the pilot
once the desired rpm is reached according to the
selected power setting.
The engine display is positioned on the instrument
panel according to customer preference. The display
shows engine speed, EGT, fuel quantity remaining, fuel consumption,
endurance, thrust percentage, battery voltage and
capacity, hours of
running time. Lights on the display indicate whether
the engine is fully extended (green), being extended
or retracted or fully retracted.
Nose Ballast System
Fixed nose ballast weights enable a minimum pilot
weight of 55kg for the pure sailplane. The ballast
system allows for configurations of 2, 4, 7, 9 and
11 kg to be added in the nose.
The sustainer installation and fuel tanks are aft of
the aircraft empty centre of mass so ballast weights
will normally be used to offset the weight of the
sustainer installation and fuel.
The standard battery in the fin will not be used
when the sustainer is installed as this also assists
with moving the centre of mass forward (and the
additional electrical power capacity is not
necessary with the Li-Ion main batteries replacing
the standard lead-acid main batteries). If fitted,
the brass hub tailwheel will be replaced with a
Vesconite tail wheel hub.