One of the planes I flew had an APU that also provided bleed air for pressurization if needed. Take off with APU as source, engine bleeds off, then switch and shut down the APU.

Jeff

At the jet I'm buying this year it is around 150 pph.

If you are a paying CJP member you can get CJPFuel for any type aircraft. http://www.cjpfuel.com/

This will cause accelerated wear for battery, start contactor, starter brushes. I used to do lots of series starts, ate up batteries, ate up my starter contactor, batteries lasted only 2 years.

I tried to measure peak current for series start, well over 1600 amps, very hard on things. I do use it when cold and no GPU.


MU2 not approved for cross gen starts. Some folks do it anyway, I've been told.

Mike C.

But battery health is.

GPU mostly saves the battery. The engine health is not improved by a GPU that much if you are under temps by a good margin anyway. If battery is cold, then you can start to risk the engine, and your engine program does not cover abuse, and a hot start is abuse.

Jets can be less to start, no prop as in TPE331. But they can't unload the fan unlike the prop at flat pitch, so there is some load there.

Mike C.

When we do a cross gen start in the C90 we wait until N1 almost peaks on the engine being started before putting the gen on for the engine running. I see folks put the gen on right away once they hit the start switch for the engine being started. That seems to draw a much higher load for a bit.
Of course, in the Citation, it's done for you. No need to manually bring on the gen.

For that reason alone, I'd opt for not having one.

Systems complexity goes up quite a bit, too.

My impression is that APU equipped airplanes are larger two pilot airplanes. Anybody know of an SP jet with an APU?

Mike C.

Cold battery is a different situation.

I know the status of my battery. I am more wary of using an unknown GPU while on the road. I have run into ones that could not carry the load or were running low on charge at the end of a day. A GPU dropping offline during a start can give you a hot start and the GPU dropping out can be more of a surprise.

At home I will do GPU starts with a known good GPU plugged into electrical service. On the road I don't bother with a GPU unless I have concerns about my battery.

You have to guard against hot starts whether using a battery or GPU.

This GPU discussion started about using a GPU on a quick turn. Cold battery argument doesn't apply there.

Depends where you go. Some CJP members have dumped CAA for CJP.

Note that CJPFuel is a member benefit and CJP gets no income from the fuel purchases. The transaction is between you and the FBO with the FBO benefiting by attracting CJP members.

Depends where you go. Some CJP members have dumped CAA for CJP.

Note that CJPFuel is a member benefit and CJP gets no income from the fuel purchases. The transaction is between you and the FBO with the FBO benefiting by attracting CJP members.

Yeah right. Chicks pee every 30 minutes. I think our pax are not the same demographic.

I measured peak current of 703 amps at the start gen when on series. I did test using the "start test" switch and not the actual start button. Perhaps the start test switch runs on 28V no matter the position of the series/parallel switch. Have to check the wiring diagram.

Re quick turns....

If one REALLY factors in all the time, it's pretty hard to do one in much less than 45 minutes.

The time lost in the descent, climb, vectoring, pattern, approach..... the ground issues, even if no one is there, the ground people are not on their toes, something goes wrong, etc., etc.

Even in a Baron it's tough.

And no matter how good the airport is a fuel stop sucks, unless there's some outstanding restaurant there which rarely happens.

AND, there's a cost for a fuel stop. Takes more fuel to stop, and start, gear cycle, tires, brakes, etc.

Range is a HUGE speed benefit.

I don't know of a Single Pilot jet with an APU, you're talking Lear 45 / 60, Excel / XLS.

The CJ4 operators love the external serviceable lav and single point refueling... probably the two things that actually make it superior to the CJ3 (most pilots like the CJ3 better)

Jason,

What kind of real world range are you seeing on the Pilatus?