What is my power source during pushback and engine start?

[Mephic 129]

Hi 

 

It's my second day with this amazing aircraft but I'm lost. I'm used to 737 procedures so I might be misunderstanding something here. I am on ground, connected to GPU. I request pushback, GPU gets disconnected and IMO I should go dark in that very moment as I have no APU running, but I don't go dark, everything still runs and I'm able to start my engines. As this is not a jet (wow what a discovery ) does it mean I don't need APU during engine start and it's just done on battery or what? I'm positive that APU is not running but I'm still starting the engines. 

 

 

EDIT: whatever... i missed the fact that there is no indication ont he button that APU isn't running. I actually presset the button and shut it down, so it seems that it's running in default panel state. 

 

I need to change my mindset here lol 

[DaveCT2003 1,820]

Normal procedure would be to bring up the APU before push, but from what you're doing the batteries are powering the aircraft and are capable of providing power to start the engines, though they won't have the amperage if you sit idle with them running for an extended period of time. 

 

I would strongly encourage you to go through the Delivery Flight Document, it will cover just about everything you can think of for a routine flight.

[Mephic 129]

You mean the extended tutorial? I was trying the simple flight first but it has lot of errors and does not mention anything about APU.

 

I will skip it and go to extended one made by q400 pilot. Thanks!

[crosswind 825]

There are 4 panel states available via the CPAN (control panel), the BOARDING panel state puts the aircraft in a RECEIVING state, where in you will still be required to start the APU if needed as the GPU is connected.

(RW) Battery starts in the Q400 are not an uncommon practice although some pilots can be somewhat skittish with this procedure.  Your disconnecting from the GPU prior to pushback will provide you with enough power to start the the engines, however being new to the aircraft your flows and other procedures maybe a bit longer than normal as you aim to become more acclimated to the aircraft.  So you could do one of two things, as the other poster mentioned, have the APU started (not online) just prior to disconnecting the GPU, once the GPU is disconnected, you can bring the APU  online OR, while being on battery power during/after the pushback, start the no.2 engine first leaving it in START FEATHER (providing there isn't an MEL preventing one from starting that engine first), bear in mind that unless you bring the engine out of START FEATHER the GENs will not come online.

 

Regarding the tutorials - The advanced tutorial is a better rendition as it was written by one our Tech Pilots and will take you from the beginning to end without issues.

Cheers

[ckyliu 1,749]

Key thing to remember is that most turboprops use an ELECTRIC starter motor (whereas most turbofans use compressed air from the APU bleed air to turn the engine over). Battery start is possible in the Q400 but it does place a big strain on the batteries so it's more normal to use APU or GPU to start the first engine.

[ibomiles 1]

Mephic - How are you coming along with getting familiar with the q400? 

[Mephic 129]

I actually familiarized myself with most of its systems now. I was just flying some circle to land manual approaches, also tried NDB radials and stuff. I learned that FMC is very powerful tool on this bird.

As far as systems goes, system description PDF proved to be really valuable tool. I feel more comfortable in Q400 now than I do in my Triple 7 or NGX so I can safely say - it is my new home and I don't plan to move out anytime soon, unless to Q300.

[clocki 2]

I'm not that pro on the plane as I'm learning too. But on my visit to a bigger Dash 8 Q400 airport I saw the following during taxi out:

GPU connected and they started No 2, then No 1 and then GPU got disconnted.

I've also seen that they have started both engines (or one for singe engine taxi) with GPU still online and then they disconnected GPU for pushback.

That's how I'm also proceeding in the sim the fuel flow for an engine in idle is not that high that it will destroy your whole fuel planning.

[crosswind 825]

On 4/15/2017 at 11:42 AM, clocki said:

I'm not that pro on the plane as I'm learning too. But on my visit to a bigger Dash 8 Q400 airport I saw the following during taxi out:

GPU connected and they started No 2, then No 1 and then GPU got disconnted.

I've also seen that they have started both engines (or one for singe engine taxi) with GPU still online and then they disconnected GPU for pushback.

That's how I'm also proceeding in the sim the fuel flow for an engine in idle is not that high that it will destroy your whole fuel planning.

Every operator has their own procedures for GPU/APU operations, and the reference that you made works great for airports that allow engine starts on the gate.  However some of the major airports in the US prohibit engine starts on the gate (unless there is no other available option).  So the prefered method (in some cases) providing the APU is working, is to run off of APU power and perform engine start(s) during the push-back or when advised to do so buy the push-back crew.  If the GPU is INOP, then with the approval from the airport authority (normally coordinated between dispatch or the crew and the Operations center for the airport) start the no.2 engine leaving it in START/FEATHER, disconnect from the GPU, then proceed with the push-back.

Cheers

[ibomiles 1]

On ‎4‎/‎23‎/‎2017 at 4:33 PM, crosswind said:

Every operator has their own procedures for GPU/APU operations, and the reference that you made works great for airports that allow engine starts on the gate.  However some of the major airports in the US prohibit engine starts on the gate (unless there is no other available option).  So the prefered method (in some cases) providing the APU is working, is to run off of APU power and perform engine start(s) during the push-back or when advised to do so buy the push-back crew.  If the GPU is INOP, then with the approval from the airport authority (normally coordinated between dispatch or the crew and the Operations center for the airport) start the no.2 engine leaving it in START/FEATHER, disconnect from the GPU, then proceed with the push-back.

Cheers

My flows use the APU during pushback and I usually start Eng#2 at the end of the pushback.  However, MCE flows will also support attaching the GPU as part of the engine start procedure.

I usually fly with GSX and MCE.   As such, I have an established set of flows I go through each time. I started with the flows provided by MCE but quickly realized they were not quite smooth enough.  So I referred back to the MJC tutorial and other sources and managed to work out a really good flow.  I now fly the Q400 w/ MCE & GSX almost exclusively.  However, I find my myself in the cockpit of the Leonardo Maddog MD82 quite often as well. I really love them both.

For those of you who like the process of Advanced programming in the FMC such as MNVRs for PVOR, SXTK, Defined WPTS and all the other features, there is a wonderful tutorial in You Tube   "The FMC Challenge | Testing the Majestic Dash 8 Q400 Pro FMS".