electrical system operational considerations Flashcards
during pre-flight inspections, what should you only operate?
only brief electrical services which require airflow past them for cooling e.g. pitot heater, landing lights.
why should ancillary electrical equipment only be turned on after the engine has started and turned off before shutting down?
large voltage fluctuations produced when the starter is engaged may severely damage sensitive electronic circuits.
why should you avoid prolonged starter operation?
as starter motors place a large drain on the aircraft battery and overheat it
intermittent use of the starter operation helps with what?
helps the battery to recover to some extent in the interval and will prevent overheating of the starter motor.
when should you release the start key or button from the START position?
immediately after the engine is running.
after startup how can you check if the alternator/generator is operating satisfactorily?
by a relatively high charge being indicated by the ammeter as the battery will require some recharging after the start.
when the battery is fully charged and the alternator is operating what should the ammeters read?
centre-zero ammeter should show a zero reading or possibly a slight positive charge.
left zero ammeters should show a reduced charge rate.
as extra circuits are switched on the ammeter reading may do what?
momentarily show an increased load.
during flight, large continuous deflection in one direction or in other in an ammeter may mean what?
a malfunction that will require immediate attention.
why should you ensure the battery master switch is OFF before leaving the aircraft at end of the flight?
leaving it on can discharge the battery overnight
if both ammeters are indicating as they would if there was a drain on the battery and are left this way the situation would mean what and how would this be read on the ammeter?
would mean that the battery will become flat.
centre-zero ammeter will indicate a constant negative reading and a zero-left ammeter will indicate a zero or abnormally low charge rate.
if there’s insufficient current from the alternator or none at all what procedure should be done?
unnecessary or less essential electrical equipment should be switched off to conserve battery and thought should be given to make an early landing.
what happens if the ammeters are indicating all the way to the right?
indicates an abnormally high positive charge rate. if there’s too much current and an excessive charge rate, the battery could overheat and create a hazard.
what if the cause of the excessive current in the ammeter is a faulty voltage regulator?
equipment such as the radio could be adversely affected.
aircraft fitted with a low voltage or ALT light will illuminate when?
when the alternator drops offline while flying.
