Section 4
Model GA8-TC 320 Normal Procedures
CASA Approved
Page 4-10 5 Feb 2009 C01-01-08
4.4.2 Starting Engine
The TIO-540-AH1A engine as installed in the GA8-TC 320 aircraft is tted with dual magnetos.
The left hand magneto is equipped with an impulse coupling to retard the ignition and provide a
strong spark for engine starting. During the start cycle when magneto/start switch is rotated to
the START position the right magneto is deactivated and the engine ignition is provided by the
left magneto only. When the ignition switch is released to the BOTH position both magnetos are
enabled into their normal operating mode.
If for any reason the battery is at the engine can be started by ‘hand propping’, albeit with
difculty. The magneto/start switch should be selected to LEFT position for hand propping.
Whilst possible, hand propping is discouraged and ground power utilising the receptacle located
adjacent to and to the rear of the pilot’s cockpit door should be used if at all possible
After starting, oil pressure should start to rise within 30 seconds in normal temperatures and
about twice as long in very cold weather. If it does not rise within this time stop the engine and
investigate the cause.
4.4.3 Taxiing
Positive control is available to the pilot when taxiing due to the direct linkage type nosewheel
steering. Care should be exercised in strong winds, particularly in quartering tail wind conditions.
As with any high wing conguration aircraft, appropriate elevator and aileron control positions
are essential during taxiing operations particularly during strong tail wind conditions.
Taxiing over loose gravel or stones should be done at low engine RPM to minimise propeller
damage.
NOTE:
At high eld elevations it may be necessary to manually lean the engine
for smooth operation during ground operations at idle engine speeds.
4.4.4 Before Take-Off
Warm Up
Most of the warm up will have occurred during taxiing and whilst conducting the Before Take-Off
checks. The engine is warm enough for take-off when the throttle can be opened without the
engine faltering.
Magneto Check
The magneto check should be made at 2000 RPM as indicated by the tachometer with the
mixture set to full rich. Select the left magneto (L) and note the RPM drop, return to BOTH until
the engine regains speed. Select right magneto (R) and note the RPM drop, return to BOTH.
Drop in RPM should not exceed 175 RPM and the difference between magnetos should not
exceed 50 RPM. Do not operate on a single magneto for an extended period, a few seconds is
usually sufcient to check RPM drop and will minimise spark plug fouling.
Propeller Check
Move the propeller control lever through its complete range of operation to ensure that it is
operating correctly and return it to the full ne (full increase RPM) position. Do not allow the
engine RPM to drop by more than 500 RPM. In cold operating conditions the propeller should
be exercised at least three times to allow warmed engine oil to circulate throughout the system.
01 Aug 2011