APU and Main Battery

What is APU (i know what it stands for and what it does in reality) but what effect does it have in IF and what does Main Battery do?

APU is the Auxiliary Power Unit. It’s what powers the aircraft when on the ground.

1 Like

Yes that is it @CPT_HILD @Liam06

1 Like

If you want to read more click below.

1 Like

Thanks everyone. What about Main Battery

The main battery is what powers all the instruments etc… but that all is because of the APU.

Here’s the proper definition.

  • Master Switch - Most often actually two separate switches, the Battery Master and the Alternator Master. The Battery Master activates a relay (sometimes called the battery contactor) which connects the battery to the aircraft’s main electrical bus. The alternator master activates the alternator by applying power to the alternator field circuit. These two switches provide electrical power to all the systems in the aircraft.
1 Like

So, in a much simpler term am I correct if I did this?

-> (wait for APU ON, automatically)
-> Engine Start
-> (Wait for engine at complete iddle)
-> Start pushback/taxi after checklist.


Yes thats correct.


No. You would turn the battery on first, then the APU.

EDIT: just to add this is exactly the same as a real aircraft. Battery goes on first, APU later. The bit that is effectively missing atm is the ground power (perhaps that will be added at some stage) so the electrical power source sequence in a real aircraft would usually be:

Battery & standby power on
Ground power connected & on
APU on about 15/20 mins before push
Pushback and engines on, switch power source to engines
APU off

The APU serves as a power and bleed air source between the point when the ground power is disconnected and when the engines are on.


From the new Infinite Flight guide

1 Like

Yes, first Main battery on, then APU start, its automatically goes in a few seconds to on and then the PFD and the other instruments are going on.
( When the Instruments are on you can start the engine(s)!


This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.