Audible alarm before landing - anyone know the reason ?

[WilloW_737 5]

Greetings

 

I am baffled by an alarm that I do not understand.  I have searched through the FCOM and FCTM without luck. 

 

Navigate 32 minutes into the video just before landing.  You will hear an audible alarm which is the autopilot disconnect (zaa zaa zaa).  This is immediately followed by another alarm (beep beep beep).

 

 https://www.youtube.com/watch?v=IXH9LhUQCIs

 

Does anyone know what this alarm is for?

 

On another note, does the NG have an alarm for the auto throttle disconnect ?

 

Thanks,    Iain

[codechris 9]

Yes it does have an alarm for the A/T disconnect

[pete_auau 1,158]

as well   as  the auto pilot  as well

[WilloW_737 5]

Yes it does have an alarm for the A/T disconnect

 

Thanks.

 

Can you confirm that the alram is identical to that heard in this video ?

 

Further, does the alarm sound everytime you disconnect the autothrottles (no matter what the altitude) or only below a certain altitude ?

 

Cheers,   Iain

[Rhinozherous 90]

Hello!

 

I'm sure it is the sound for autothrottle disconnect. As the autothrottle arm light on the MCP goes out right in the moment of the beep. And it is the only thing you also want to disconnect after the CMD I think

 

Regards,

[codechris 9]

Actually I've just checked and I don't hear that noise, or any noise when disconnecting A/T.

 

That was with the default livery though...I wonder if it's an option

 

What else do you have running in the sim?

[WilloW_737 5]

Thanks for your comments.

 

It could be an option - not sure.

 

Perhaps a real-world NG pilot, if they read this , this can chime in.

 

The AFDS illumninates as the Autothrottle are disengaged - suggesting that the noise is indeed an A/T disconnect alarm.   

 

I cannot comment on what options are used in the video as this is NOT my sim. 

 

I am trying to determine what the alarm is for, and then whteher it is a cutomised airline option.

 

Thanks,   Iain

[codechris 9]

You do see the red flashing on on A/T disconnect, but in the PMDG NGX I only hear the noise from Autopilot disconnecting. Maybe it is a feature of that sim software

[scandinavian13 5,192]

I believe they've added some non-standard sounds into their sim. When referencing what it should be like, it's usually best to reference videos of actual line flying and not sim enthusiasts.

 

There's also an intermittent chime, which I'm unsure what that's related to. Almost seems like an FA call button in the cabin, but I've never been on a flight with that many calls.

 

Go to 10:00 in this video:

https://www.youtube.com/watch?v=A8c_q5bRB6k

 

The AP disco alarm sounds, and if you watch for the AT light, it silences without alarm. I'm curious where they got that alarm, but I don't think it's from Boeing. It's not even from Airbus from what I can tell.

[UAE77W 16]

That's the A/T disco from the B757/B767. https://www.youtube.com/watch?v=IK9SzuKNXic

 

Skip to 2:00  B)

[scandinavian13 5,192]

 

 

That's the A/T disco from the B757/B767.

 

Nope. AP Disco - watch the AP light. He also calls AT off prior to the sound, which is fitting, again, because I've never heard a Boeing with an AT disco sound.

[UAE77W 16]

Nope. AP Disco - watch the AP light. He also calls AT off prior to the sound, which is fitting, again, because I've never heard a Boeing with an AT disco sound.

 

Ok, thanks for clarification. But on this video the AP disco sounds different. https://www.youtube.com/watch?v=0_OAH9iRh1I Skip to 02:55. Seems the B757 has different AP disco sounds.

 

And what's with the B744 and B777. They both have A/T disco sounds. https://www.youtube.com/watch?v=TImK-oNY6-s 01:05

[scandinavian13 5,192]

 

 

Seems the B757 has different AP disco sounds.

 

Company options. If you have our 777, you can swap between siren and wailer options.

[codechris 9]

Trouble is, you don't really know exactly what they have running under the bonnet unless you ask. When it comes to big sims, it could be a big range of things

[kevinh 409]

The triple beep sound is the master caution alert from EICAS equipped Boeings (747-400, 757/767, 777). It's in the PMDG 777 too. It shouldn't be heard on a 737 but the sim in the OP's video could have been modified for some reason.

 

The 777 A/T disconnect causes a master caution triple beep too, at least according to the FCOM.