Depends on the aircraft, but that's definitely true.

 

...particularly in the case of the ERJ, which really makes me want to cry as blood drips from my ears.  If one could imagine the sound of the devil with a terrible whistle, that would be the ERJ APU.

It might also be the #1 hyd pump. That combo will make ears gush blood. TSA has a floater paint scheme erj that can be heard all around CLE.

Is it even possible to power up the plane from cold & dark with external power? I can't access the FMC to connect external power when I put just the battery on, like I can in the NGX for instance. So I'm forced to start the APU to get power.

I shall point you to my signature.

 

Introduction, to be more precise, and also tutorial, I believe.

Is it even possible to power up the plane from cold & dark with external power? I can't access the FMC to connect external power when I put just the battery on, like I can in the NGX for instance. So I'm forced to start the APU to get power.

Press Menu. Hold down. Keep holding it... keep holding it. 5 seconds... aah there we go... The Menu page is up, even if the rest of the FMC isn't there yet.

Emirates is running the APUs throughout the whole turnarounds as standard procedure.

 

Because they got the mula    :lol:

Because they got the mula :lol:

The joy of being based in an oil rich country but AA does the same here in ORD they don't even bother hooking up the GPU on 777's here.

It might also be the #1 hyd pump. That combo will make ears gush blood. TSA has a floater paint scheme erj that can be heard all around CLE.

 

haha - nah.  From about four years of ramp time, it's definitely the APU that I hate most, though the hyd pump just adds to the cacophony.

 

...and I think I know just the ERJ.  Having worked UAX ground handling, I'm sure I saw it a few times.

Emirates is running the APUs throughout the whole turnarounds as standard procedure.

 

Not really...

Emirates runs the APU at STD-20 either in DXB and outstations as standard procedure (unless specified otherwise by more restrictive airport procedures, or in case of severe heat Pre-Conditioned Air cannot handle).

Obviously, fuel price and noise level are the strongest reasons why APU start-up is usually delayed to the very last minutes

I've seen at LIMC 2 777 one from Emirates and another i don't remember the company at the gate all two connected with EXT power at gate before start 

Airlines have really gotten away from using APU's for ground operations except during an engine start for numerous reasons. Fuel is the main one. An APU under load can burn over 150 Lbs/hour.Many airports now have PC air units on the jet bridge so using the APU for AC or heat is no longer needed. There are numerous advantages to doing this. Not the least of which is less maintenance costs associated with using the aircraft bleed and environmental control systems to provide conditioned air during ground operations. Fuel costs have gotten to the point that many airlines now conduct single engine taxis on taxi out to the runway. Regards

The only reason these Middle East carriers keep the APU running is because it gets so hot in the summer, everywhere else they use ground power whenever possible just like everyone else. Whilst Flying from Qatar to Bahrain on Monday some dude next to me was complaining that the air conditioning was off while the engines where starting, he even had a go at a male flight attendant

Thai Airways couldn't get their APU started at YPPH in a brand new A330 this year. So they did a ground power start on engine two with the external ground cart (high pressure compressors) (mobile) on the engine one side and then once the engine was running the ground services disconnected the external ground cart and started pushback where the bleed air from Engine Two was used to start the engine one. That was interesting, as I believe that is uncommon.

 

Anyhow I have seen the Ansett 737 years ago at Kalgoorlie leave their APU on with their airstairs down as I believe there was no equipment to hook up or it was just they didn't care. It is a very small airport, it is more an aerodrome than anything. I think that was standard procedure back then it might have changed by now.

 

At YPPH and airports in Australia I think the Ground Power is used almost all the time at Major Airports, like YBBN, YSSY, YMML and YPPH etc. The APU is started ten minutes or so before push and that is normal for me.

 

I think Asia is the same, those new airports have everything up there. Anyone disagree?

 

There are 2 or even 3 aerobridge per gate (now 3 for the A380s). Hong Kong's airport is absolute luxury. I think every gate has 2 Aerobridges.

 

Here is Captain Lim's take on it who used to work for a major Asian Airline and is a friend of mine: http://www.askcaptainlim.com/component/content/article/13-general/1176-why-the-apu-is-kept-running-and-wasting-fuel-on-ground.html