I don't "need" one. I just choose to use it. I never said I "needed" it.

I'm sure all the KA's and Citations you speak of have an outlet for a GPU right?

Yes they do. So does my Cessna 182.

I was just curious as to why you use one. There is a PC12 locally that
does not use one.

How many seconds approx is the difference in engine start time with the batteries vs with a GPU for you?

It saves batteries and promotes cooler faster engines starts. In cold conditions, especially if you have lead acid batteries, a GPU can be a necessity.

I use a GPU when I can. Must be engine or AC line powered (battery carts are generally no good), and free. About 65% of my starts are GPU, all at my home base and about 1/3rd of them away.

Since you have TPE331 engines, which are harder to start, suggest you consider trying a GPU.

The PC-12 engine is a large block PT6, so not quite as easy to start as the small ones, but still easier than a TPE331.

Mike C.

I don't like to bring sand to the beach.

Having an airplane is nice....... "Hey Jason, fly me out and you can stay at my house"

If the GPU is sitting there, why wouldn't you use it?

I don't think there is a difference in start time.

With the GPU my avionics are all powered up and work as though the engine is on. I can get clearance, lower flaps and run everything to get the plane set to fly. Then I can start the engine and taxi.

If I don't use the GPU, after engine start I gotta wait a minute for all the avionics to power up. I can't taxi while they power up because it throws everything off. Also heat and AC work with the GPU hooked up.

99% of the time, there GPU is sitting there and I tell them to hook it up. No big deal. I'm not seeing the downside.

Different situation from mine. I frequent many locations where GPU's are not available. I also do not frequent cold weather areas where a GPU would be a help.

I have a hot switch that I use for getting conditions and clearance without turning all avionics on.

if you have electric air I can see a big use of the GPU to cool the cabin. I have ACM's so a GPU would not help with that.

Often at busy times one has to wait for the fuel truck and I have seen people have to wait for the GPU as well. I figure the less equipment I have to wait for the better.

I am sure you can run the same way, if you have to wait for a GPU you can start and go on batteries if you want.

I don't have to use a GPU. I choose to. Never had a problem getting one. I call the FBO on the way to the airport and tell them to pull the plane, put gas in it and hook up the GPU.

I feel like I'm speaking Chinese. Is this really such a big deal?

Hi Jason,

I put 200 of my ~700 hours last year on a 2013 NG. I haven't used a GPU once. I'm not trying to get in your face here, just comparing your technique to how I was trained...
It's my understanding (and observation) that BATT2 is completely reserved for the start. No matter what you do on BATT1, you've got a total freshie for the start.

So, I:

15-30 min before pax arrive, I energize STBY BUS, get ATIS, clearance, and program every known piece of flight plan data into the FMS. I also log the time, and voltages of BATT1 and 2.

When I see the pax coming, I test and start the ESIS (EPS?) and energize BATT 1 and BATT 2.

I get the pax and bags loaded, all the while the systems are booting and CAS messages clearing.

When everyone's in, I punch the start button before I even buckle in. By the time I am buckled in, I'm ready to taxi and ready to depart when reaching the runway.

The ability to do it all this way is one of the many reasons I LOVE this airplane.

I guess what I'd like to know is why a GPU (unless the airplane has sat for weeks) when BATT2 is at full charge? It seems like more steps to me...

Regards,
Bill

I'd like to add my reasoning for asking, now that I re-read the post, it is starting to look something like a grand jury proceeding!

Jason, you just became one of two NG pilots who use GPU's quite regularly...

The first, blew out a junction box at some point and was convinced that it could have been avoided by starting with a GPU. I have not been able to trace that logic, although I have less working knowledge of things electrical than Martha Stewart.

I'm trying to pick up more data, in case I'm missing something, that's all.

I will stipulate that a GPU start is always batter than a battery start.

The answer of: "It makes me feel better", is totally sufficient, and comprehensible to me.

Yeah. I'm not that guy. I'm not getting paid to do this. The line guys have the GPU already hooked up when I get there.

I know how to turn my airplane on both with and without a GPU. I don't see the downside of my way.

I hangar with Epps. They're the Pilatus dealership. Loads of PC12's at PDK. Everyone uses GPU. The sales guys train to use GPU. Like I said. Why NOT use a GPU?

Cool, thanks. I get all that.

Gorgeous paint, BTW.

Usually the GPU is free if you buy x gallons of gas. Why not use one? One less battery start. Last time I checked they don't give new free batteries when buying gas. We use them all the time on our phenom 300 and citation encore fleet. There is no down side, totally with Jason on that.

I think you've got it backwards..

Especially in the winter, the NE sucks.

Thank you. I actually don't like it but it gets lots of compliments. Downtime for a paint job is unreasonable.

Sorry to continue the thread drift on the GPU talk but this wasn't something I had considered as it relates to operating a turbine. I always fly to the very nearest airport closest to my destination and 50% of the places I fly are little airports without a great deal of services or staff, let alone GPUs.

For Jason and others who like to use GPUs, do you purposely seek out airports with more services that are likely to have GPUs available, even if it means more drive time to your final destination?

Also, someone mentioned that the big block PT6's and Garrett's are a bit more difficult to start and that a GPU is very helpful in those cases. Is this not as much of a consideration for the smaller PT6's like Meridians and TBMs?