embraer175e2
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Atr's 600 series hotel mode VS bombardierq turboprop nextgen APU

Tue May 16, 2017 1:39 pm

Guyys overall ATR has the more economic product. But what about the noisy hotel.mode that everybody hates at all airports I have been at? Isn't a new generation APU just a better tool for health of employees and savings in use of expensive ground equipment?
 
 
embraer175e2
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Re: Atr's 600 series hotel mode VS bombardierq turboprop nextgen APU

Tue May 16, 2017 1:54 pm

Not to talk about the hazards of a running hotel mode during baggage loading and fueling. You shut it down 8 out of 9 times on ground during normal ops .
 
StereoTechque
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Re: Atr's 600 series hotel mode VS bombardierq turboprop nextgen APU

Tue May 16, 2017 8:11 pm

The Flying Engineer has a nice comparison between both the turboprops.
An APU will always be preferred over the Hotel mode, but since ATR has designed the aircraft with hotel mode to replace the APU, they will stick to the plan.
I hope they come up with a higher capacity turboprop with an APU.
Looking California.. Feeling Minnesota.... R. I.P. Chris Cornell...
 
embraer175e2
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Re: Atr's 600 series hotel mode VS bombardierq turboprop nextgen APU

Wed May 17, 2017 7:11 pm

StereoTechque wrote:
The Flying Engineer has a nice comparison between both the turboprops.
An APU will always be preferred over the Hotel mode, but since ATR has designed the aircraft with hotel mode to replace the APU, they will stick to the plan.
I hope they come up with a higher capacity turboprop with an APU.

Agree . nothing can replace an APU.
 
 
baje427
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Re: Atr's 600 series hotel mode VS bombardierq turboprop nextgen APU

Thu May 18, 2017 2:30 pm

Well based on sales I dont think the Hotel mode is a big factor the ATR is outselling the Q400 by quite a large margin.
 
FlyHossD
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Re: Atr's 600 series hotel mode VS bombardierq turboprop nextgen APU

Thu May 18, 2017 6:31 pm

embraer175e2 wrote:
Agree . nothing can replace an APU.


As I recall, an inoperative "Hotel Mode" was a piece of this accident:

https://app.ntsb.gov/pdfgenerator/Repor ... l&IType=LA

Without a functional prop brake (and no APU), the crew was running the right engine with the prop feathered. The flight was normally an EMB-120 - WITH an APU - so some believed that the employee wasn't expecting an spinning propeller when she went towards the right main gear to pull the chocks.
My statements do not represent my former employer or my current employer and are my opinions only.
 
embraer175e2
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Re: Atr's 600 series hotel mode VS bombardierq turboprop nextgen APU

Thu May 18, 2017 7:52 pm

baje427 wrote:
Well based on sales I dont think the Hotel mode is a big factor the ATR is outselling the Q400 by quite a large margin.

The ATR is much cheaper in list price. And 30% less fuelburn. That's the winner right there.
 
embraer175e2
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Re: Atr's 600 series hotel mode VS bombardierq turboprop nextgen APU

Thu May 18, 2017 7:54 pm

[code][/code]
baje427 wrote:
Well based on sales I dont think the Hotel mode is a big factor the ATR is outselling the Q400 by quite a large margin.


Also the option of a common cockpitcrew for both at42-72.
 
VSMUT
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Re: Atr's 600 series hotel mode VS bombardierq turboprop nextgen APU

Fri May 19, 2017 8:01 pm

embraer175e2 wrote:
baje427 wrote:
Well based on sales I dont think the Hotel mode is a big factor the ATR is outselling the Q400 by quite a large margin.

The ATR is much cheaper in list price. And 30% less fuelburn. That's the winner right there.


And they gain those 30% and lower list price by saving, among other things, the APU. APUs are heavy and really expensive, and is yet another maintenance item that is required to work before every flight. Fitting an APU down in the tail also means that you have to plumb the aircraft with a more complex fuel system that leads all the way there, along with fuel pumps and all the electrical wiring and so on. As it is today, the entire fuel system of the ATR is pretty much found in the wings, centre fuselage and gear fairings.
 
xdlx
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Re: Atr's 600 series hotel mode VS bombardierq turboprop nextgen APU

Thu Nov 23, 2017 12:11 am

VSMUT wrote:
embraer175e2 wrote:
baje427 wrote:
Well based on sales I dont think the Hotel mode is a big factor the ATR is outselling the Q400 by quite a large margin.

The ATR is much cheaper in list price. And 30% less fuelburn. That's the winner right there.


And they gain those 30% and lower list price by saving, among other things, the APU. APUs are heavy and really expensive, and is yet another maintenance item that is required to work before every flight. Fitting an APU down in the tail also means that you have to plumb the aircraft with a more complex fuel system that leads all the way there, along with fuel pumps and all the electrical wiring and so on. As it is today, the entire fuel system of the ATR is pretty much found in the wings, centre fuselage and gear fairings.


The ATR could locate the APU in the Rear fairing of the gear, across fuselage like the 727. No need to get the CG out of wack.
 
VSMUT
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Re: Atr's 600 series hotel mode VS bombardierq turboprop nextgen APU

Thu Nov 23, 2017 9:10 pm

xdlx wrote:
VSMUT wrote:
embraer175e2 wrote:
The ATR is much cheaper in list price. And 30% less fuelburn. That's the winner right there.


And they gain those 30% and lower list price by saving, among other things, the APU. APUs are heavy and really expensive, and is yet another maintenance item that is required to work before every flight. Fitting an APU down in the tail also means that you have to plumb the aircraft with a more complex fuel system that leads all the way there, along with fuel pumps and all the electrical wiring and so on. As it is today, the entire fuel system of the ATR is pretty much found in the wings, centre fuselage and gear fairings.


The ATR could locate the APU in the Rear fairing of the gear, across fuselage like the 727. No need to get the CG out of wack.


Already packed with air conditioning packs, landing gear and hydraulics.
 
WIederling
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Re: Atr's 600 series hotel mode VS bombardierq turboprop nextgen APU

Fri Nov 24, 2017 8:19 am

FlyHossD wrote:
Without a functional prop brake (and no APU), the crew was running the right engine with the prop feathered. The flight was normally an EMB-120 - WITH an APU - so some believed that the employee wasn't expecting an spinning propeller when she went towards the right main gear to pull the chocks.


Instrument flight on the ground.
The lady should have calibrated her map model "how things should be" with a peek at reality?
Murphy is an optimist
 
CanadianNorth
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Re: Atr's 600 series hotel mode VS bombardierq turboprop nextgen APU

Wed Nov 29, 2017 1:48 am

xdlx wrote:
The ATR could locate the APU in the Rear fairing of the gear, across fuselage like the 727. No need to get the CG out of wack.


I don't have any documentation to back myself up, but I do clearly remember from the ATR 42-300/320 maintenance course our instructor told us that the story goes when first designing the ATR they originally planned to put an APU in the fairing just behind the starboard main gear, but then dropped the idea in favour of Hotel mode.

I'm pretty sure there isn't much going on in that space on the ATRs now. If I remember correctly forward of each main gear is an air conditioning bay, aft port side is hydraulics, and aft starboard side is not much.

I'm still not sure where I stand on the hotel mode vs APU. I like the idea that hotel mode is much simpler and lighter, but it really is scary to work around on the ramp. When the ATRs were first brought up here we were clearly told "prop brake always works great, never ever trust it."

Also we don't use hotel mode when towing (I can't remember if that's a company thing or an ATR thing though), where as with our Boeings we usually run the APUs so we can have some heat, lights, radios and hydraulic pressure when we tow through the black hole between our hangars and the terminal. I will give ATR a bonus point though for that push button 30 second hydraulic pump straight off the battery for to have some hydraulic brake pressure when being towed around in a cold dark airplane, that part actually was a pretty good idea.
HS-748, just like a 747 but better!
 
T prop
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Re: Atr's 600 series hotel mode VS bombardierq turboprop nextgen APU

Thu Nov 30, 2017 7:48 pm

The Q400's apu is better. You can't refuel the 72 with it running, you can't use the service door, the nose of the airplane needs to be into the wind or you'll get a nac hot warning, it's just about useless in hot conditions for cooling the cabin and it uses more fuel than the Q's APU. The APU on the Q is cat D MEL, it can be inoperative for 120 days and it can be deferred in minutes. ATR Hotel mode is a cat C MEL it can be inoperative for 10 days and takes a while to defer, the brake unit must be removed from the engine and the opening capped.
 
T prop
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Re: Atr's 600 series hotel mode VS bombardierq turboprop nextgen APU

Thu Nov 30, 2017 8:21 pm

CanadianNorth wrote:
xdlx wrote:
The ATR could locate the APU in the Rear fairing of the gear, across fuselage like the 727. No need to get the CG out of wack.


I don't have any documentation to back myself up, but I do clearly remember from the ATR 42-300/320 maintenance course our instructor told us that the story goes when first designing the ATR they originally planned to put an APU in the fairing just behind the starboard main gear, but then dropped the idea in favour of Hotel mode.

I'm pretty sure there isn't much going on in that space on the ATRs now. If I remember correctly forward of each main gear is an air conditioning bay, aft port side is hydraulics, and aft starboard side is not much.

I'm still not sure where I stand on the hotel mode vs APU. I like the idea that hotel mode is much simpler and lighter, but it really is scary to work around on the ramp. When the ATRs were first brought up here we were clearly told "prop brake always works great, never ever trust it."

Also we don't use hotel mode when towing (I can't remember if that's a company thing or an ATR thing though), where as with our Boeings we usually run the APUs so we can have some heat, lights, radios and hydraulic pressure when we tow through the black hole between our hangars and the terminal. I will give ATR a bonus point though for that push button 30 second hydraulic pump straight off the battery for to have some hydraulic brake pressure when being towed around in a cold dark airplane, that part actually was a pretty good idea.


Hotel mode can't be used while towing because one of the conditions to be met for Hotel mode is that the parking brake must be set. I do like ATR's use of the hydraulic pump to pressurize the park brake accumulator. Not only do you have the pump run for 30 seconds if the master is on, but in a dark airplane all you do is press the button and hold it. The pump comes on and the pressure gauge is powered as long as you hold the botton down. This beats the Q's having to go grab the handle and pump the handpump in the right wheel well.
 
VSMUT
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Re: Atr's 600 series hotel mode VS bombardierq turboprop nextgen APU

Thu Nov 30, 2017 10:33 pm

T prop wrote:
The Q400's apu is better. You can't refuel the 72 with it running, you can't use the service door, the nose of the airplane needs to be into the wind or you'll get a nac hot warning, it's just about useless in hot conditions for cooling the cabin and it uses more fuel than the Q's APU.


Depends what you use the plane for. In some rough 3rd world airport in the middle of nowhere without GPUs, you would be correct. But most airports in the world feature GPUs these days, so the point is void. Dash-8 or ATR, they will both receive a GPU within moments of parking at the stand, so no need for APUs or Hotel mode.

T prop wrote:
I do like ATR's use of the hydraulic pump to pressurize the park brake accumulator. Not only do you have the pump run for 30 seconds if the master is on, but in a dark airplane all you do is press the button and hold it. The pump comes on and the pressure gauge is powered as long as you hold the botton down. This beats the Q's having to go grab the handle and pump the handpump in the right wheel well.


Also great for operating the cargo door :) On some cargo conversions, that's our only way in.
 
CanadianNorth
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Re: Atr's 600 series hotel mode VS bombardierq turboprop nextgen APU

Fri Dec 01, 2017 12:53 am

T prop wrote:
The Q400's apu is better. You can't refuel the 72 with it running, you can't use the service door, the nose of the airplane needs to be into the wind or you'll get a nac hot warning, it's just about useless in hot conditions for cooling the cabin and it uses more fuel than the Q's APU. The APU on the Q is cat D MEL, it can be inoperative for 120 days and it can be deferred in minutes. ATR Hotel mode is a cat C MEL it can be inoperative for 10 days and takes a while to defer, the brake unit must be removed from the engine and the opening capped.


Just curious what it is about the 72 that prevents fueling in hotel mode? I've refueled ATR 42s on numerous occasions with hotel mode running.

The aft service door can also be used, but generally isn't because people tend to get upset when exhaust goes pouring into the cabin. As for the wind and the MEL situation yes, those can be an issue with hotel mode. Definitely need to pay attention to where the wind is coming from when planning aircraft parking. Heating/cooling seems to work okay, but again 42 vs 72 might be different.
HS-748, just like a 747 but better!
 
VSMUT
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Re: Atr's 600 series hotel mode VS bombardierq turboprop nextgen APU

Fri Dec 01, 2017 9:27 am

CanadianNorth wrote:
T prop wrote:
The Q400's apu is better. You can't refuel the 72 with it running, you can't use the service door, the nose of the airplane needs to be into the wind or you'll get a nac hot warning, it's just about useless in hot conditions for cooling the cabin and it uses more fuel than the Q's APU. The APU on the Q is cat D MEL, it can be inoperative for 120 days and it can be deferred in minutes. ATR Hotel mode is a cat C MEL it can be inoperative for 10 days and takes a while to defer, the brake unit must be removed from the engine and the opening capped.


Just curious what it is about the 72 that prevents fueling in hotel mode? I've refueled ATR 42s on numerous occasions with hotel mode running.

The aft service door can also be used, but generally isn't because people tend to get upset when exhaust goes pouring into the cabin. As for the wind and the MEL situation yes, those can be an issue with hotel mode. Definitely need to pay attention to where the wind is coming from when planning aircraft parking. Heating/cooling seems to work okay, but again 42 vs 72 might be different.


The ATR 42 fueling point is located under the wing, outboard of the engine. On the ATR 72 they moved it onto the righthand gear fairing, right up by the hot exhaust and the propeller that is locked in place by the not to be trusted propeller brake. :hot:
 
CanadianNorth
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Re: Atr's 600 series hotel mode VS bombardierq turboprop nextgen APU

Fri Dec 01, 2017 6:32 pm

T prop wrote:
The ATR 42 fueling point is located under the wing, outboard of the engine. On the ATR 72 they moved it onto the righthand gear fairing, right up by the hot exhaust and the propeller that is locked in place by the not to be trusted propeller brake. :hot:


Makes sense I suppose, thanks! The 42 the hose goes on the wing outboard of the engine, just the fuelling control panel in the gear fairing. It's not too bad there, behind the prop but in front of the exhaust, and you're just walking yourself over not dragging a hose and ladder. Definitely need to maintain a 10/10 on the careful level with that prop only a couple feet away though, as mentioned earlier with the prop brake we had it drilled into us "works great, never trust it". When the pilots disengage the prop brake that prop does spool up pretty much right now...
HS-748, just like a 747 but better!

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