Mahindra GIPPSAERO GA8-TC 320 - Page 49

CASA Approved
C01-01-08 5 Feb 2009 Page 3-13
Section 3
Model GA8-TC 320 Emergency Procedures
With the alternator off line the battery will be supplying the required electrical power. To conserve
battery power the Bus 2 Master should be switched off. If ight with no electrical services is safe
the Bus 1 Master Switch may also be switched off to further conserve battery power. Refer to
Figure 7-3 in Section 7 for details of what items of equipment are powered from each bus.
2. ILLUMINATION OF ALTERNATOR (“ALT”) WARNING LIGHT Illumination of this amber
caution light indicates that the alternator is not providing electrical power, or the system voltage
has dropped below a nominal 12.5 volts. Refer to “Insufcient Rate of Charge” above for
symptoms, possible causes, and actions to be taken.
3. EXCESSIVE CHARGE RATE It is quite normal to have a relatively high charge rate when
the battery is being recharged after an engine start, particularly if the battery was not fully
charged to begin with. However, should the ammeter indicate a signicantly higher charge rate
than normal after approximately 30 minutes since engine start, it is possible that there has
been a failure in the voltage regulating system. Continued operation with an excessively high
alternator output voltage will eventually overheat and damage the battery as well as causing
damage to any electronic/avionics systems that require a nominal 14 volts for their operation.
In this event the Bus 2 Master Switch should be turned off and operation continued on Bus 1
and battery power alone. Consideration should then be given to landing at the nearest practical
aireld to have the problem investigated.
4. CIRCUIT BREAKERS Failure of an individual circuit will, in most circumstances, result. To
ensure a permanent fault exists in the circuit the breaker should be reset once. If the breaker
again pops the circuit is faulty and the ight should be continued without that service.
5. ALTERNATOR INDEPENDENCE Usually battery power is required to initially excite the
alternator. However, the GA8-TC 320 features a circuit incorporating a capacitor to provide
an independent source of initial electrical energy to the alternator should the battery fail. The
capacitor circuit operates whenever the Bus 2 Master Switch is selected from OFF to ON. The
alternator then provides the energy for the eld current and recharges the capacitor.
6. ELECTRICAL FIRE IN FLIGHT An electrical re is an extremely rare event as any ‘short
circuit’ that occurs should result in opening of the circuit/switch breaker that protects that
individual circuit. In the event of a failure of a circuit/switch breaker such that it will not terminate
electrical supply a simultaneous failure of a component or wiring in that circuit could cause
overheating and subsequent re. Initial indications of overheating will be a slight electrical
heating smell. This will be followed by a stronger electrical burning smell, then indications of
smoke and in the worst case; ames.
At the rst indications of overheating a preventative measure against an electrical re starting
is to switch off Bus 2 Master Switch, which controls the non essential electrical loads and the
alternator, and ight continued cautiously on the Bus 1 services utilising battery power alone.
However, if there are any indications of the re continuing, both master switches should be
turned off immediately and the aircraft landed as soon as possible.
01 Aug 2011