APU sound stays on after turning it off A330-Neo

It stays on longer than that

1 Like

I’m pretty sure that ringing voice is the airport sound. I’ve heard it and it’s does sound like that.

@Skonert I think we just don’t know what it is, so I would keep flying and we should stop speculating because we are just guessing at this point. If you hear it again, take note of the conditions in which you heard it. I will look a little bit more into this, but it doesn’t seem like a pressing issue because no one can replicate it.

Sounds like ambient airport noise. But not 100 % sure of that. Try your apu on and off in exterior view in different locations and with weather set to zero wind
see if that makes a difference ?

Unfortunatly, I won’t try anything anymore if it means that they will not look into it anyway…

Having a definite yes or no answer to whether the bug the OP may have discovered is correct or not would be the first priority before having the topic closed. Just saying “We didn’t believe you the first time” isn’t very helpful becuase a bug could be just pushed out of the way unknowingly 🤷‍♂️


Moving on, I believe I have found your issue.

If the Main Battery is on and APU is started, turning the Main Battery off during any point of the APU’s starting procedure, it continues the startup and running sound but does not have any affect on what the APU switch is selected to.

This means you might have turned the Main Battery off at some point when starting the APU, it could even be a quick misclick when setting up. I have attached a full video to show the sound and affect of this bug.

I can fortunately promise you that my device luckily doesn’t render at 144p quality nor have such low FPS. The in built recorder is pretty naff. Video provides all that is needed, I switch the Main Battery off quickly and it is covered by the APU options so do keep a close eye.

Unlisted video

7 Likes

I will do a more elaborate video when I land at SBKP to compare the airport noise to the APU so that you can all compare.

I know what happens, just turn the battery on while the APU is off and it will stop

2 Likes

Wow really? I’m going to try that when I land in 50 min.

1 Like

Yes, I realised about this issue months ago and since then I turn off APU first and then the battery

That’s why it happens, I am aware that I turn off the APU before the battery but wasn’t certain it was because of that. Although, it still looks like a small unintentional bug that depending on how busy the staff are, can look into it.

@IF-Mallorca yep you’re right! After experimenting on the third test it resulted in what you described! I’m going to share it now.

2 Likes

Great! I’m glad to have helped you