Pilot’s Operating Handbook VH-SJH Chapter 3
AIRCRAFT SYSTEMS
1 Electrical Systems
Electrical energy is supplied by a 12 volt direct current system, powered
by a 20 amp engine driven generator. A 12 volt, 24 amp hour battery, carried in a
battery compartment on the starboard engine side of the firewall supplies current
to the system when the generator is inoperative. Access to the battery is obtained
by removing the engine cowl.
Generator output is controlled by a voltage regulator on the front face of
the firewall. A cut-out unit incorporated with the voltage regulator
prevents feed back from the battery to the generator when the engine is stationary
or running below 1600 rpm. A generator isolation switch is provided
on the right side of the instrument panel.
Engine self starting is by means of an electric direct cranking “Bendix”
starter, which draws power only from the internal supply.
A master switch also situated on the right side of the instrument panel controls
the entire electrical system, except the magneto powered ignition system. When
starting the engine either electrically or by hand swinging the propeller, the
switch should always be on. If, after starting the engine the switch is off, the
electrical services including the radio, will be running direct from the generator
and will therefore fade out when the throttle is closed in flight.
Power from the aircraft source is also provided for the auxiliary fuel pump
and fuel gauge. On-off switches for these services are positioned on the
right side of the instrument panel adjacent to the master and generator isolation
switches.
An ammeter placed to the left of the master switch shows the rate of charge to
the battery. Any excessive reading should be considered abnormal and the
generator isolated as soon as possible.
2 Vacuum System
There is no vacuum system. All instruments are electrically driven
.
Pilot’s Operating Handbook VH-SJH Chapter 3
AIRCRAFT SYSTEMS
3 Fuel System
Fuel
Tank
Fuel is carried in a metal tank mounted in the top centre section of the fuselage
aft of the firewall providing a total fuel capacity of 83 litres.
A filler neck and cap protrudes through the top of the fuselage.
To test for decontamination a spring–loaded drain valve is located centrally
underneath the fuselage in an easily accessible position. A system of drainage
channels at the bottom of the tank leading to a sump and thence to the drain point
ensures that any foreign substance can be detected. A fuel filter drain is located
at the bottom of the fire wall on the starboard side.
Fuel venting
The tank is vented to the atmosphere through a vent pipe installed in the
filler
cap.
Fuel contents gauge
An electrically operated fuel gauge mounted on the right side of the
instrument panel shows contents.
Fuel pumps and priming
An engine driven fuel pump is mounted at the front of the engine. Fuel to this
pump flows from the tank under gravity through suitable plumbing and a filter on
the forward face of the firewall.
An electric auxiliary fuel pump supplying fuel to the carburettor through the
same system assists in starting the engine and prevents fuel starvation and
subsequent engine stoppage should the driven pump fail.
